The Swahili Civilization in Eastern Africa
- Elgidius B. IchumbakiElgidius B. IchumbakiUniversity of Dar es Salaam
- and Edward PollardEdward PollardDiscovery Programme: Centre for Archaeology and Innovation Ireland
The urbanization and globalization being experienced in Africa in this early 21st century have deep foundations in the continent’s history. In Sub-Saharan Africa, for example, theories on the origin of urbanization have developed through the 20th century from an external origin emphasis. There was little recognition of the greater part played by the local people. The producers of these cultures engaged in activities shaped by the environment and sociocultural, political, and economic connections. For instance, in Eastern Africa, Iron Age people became united by language and religion, and exploited the coast and sea during the medieval period (from the end of the early Iron Age c. 500 ce to the arrival of the Portuguese at the end of the 15th and to the early 16th century). Iron Age people traded with inland Africa, East and Southern Asia, and Europe, producing what has become popularly known as the “Swahili civilization.” This civilization along the coast of Eastern Africa is marked by material culture of iron working, cloth production, pottery, beads, and glass as well as monumental constructions that range from stone-built mosques, tombs, and palaces. A maritime trade assisted by seasonally reversing monsoon winds exported gold, slaves, animal skins, ivory, and mangrove poles from Eastern Africa and imported beads, porcelain, and silks. The evidence that marks the Swahili civilization is spread over an area that extends along the coast of Eastern Africa about 3,000 km from Mogadishu (Somalia) in the north to Inhambane (Mozambique) in the south. The Swahili civilization locale also includes the islands of Unguja (Zanzibar), Pemba, Mafia, Comoros, and northern Madagascar. Some remnants marking the Swahili civilization include UNESCO World Heritage Sites of Lamu Old Town, Zanzibar Stone Town, Ruins of Kilwa Kisiwani and Songo Mnara, and Ilha de Mozambique. The civilization continues in this early 21st century with its oral traditions and maritime technology that are testimony of coastal Swahili culture continuing through Eastern Africa’s social and economic challenges.
Evidence of a historic international trade extends along the coastline of about 3,000 km of Eastern Africa, extending from Mogadishu in Somalia to Inhambane in Mozambique (figure 1), and continues to attract the attention of various scholars including archaeologists, historians, anthropologists, social linguists, and ethnographers. There are several reasons as to why this coastline and its littoral continues to be of interest to diverse scholars, but two seem more convincing. First, the area is dotted with monumental structures ranging from major stone buildings, such as palaces and mosques, to single constructions, such as tombs and underground freshwater wells. There are also historic documents from classical, Arab, and Portuguese sources, local oral traditions, as well as poetry, which reveal extensive maritime knowledge the Swahili had and their engagements in global trading systems. Archaeologists and anthropologists have reported material culture that includes stone tools and ceramics from around the Indian Ocean; glass, stone and shell beads; copper coins; iron knives and bronze rings; as well as glass beakers. Likewise, there are exceptional navigational support constructions such as causeways, towers, and landing places. Some dive activities conducted along the coast of Tanzania and Kenya have also reported remains of shipwrecks along with stone anchors. Of much importance, the communities inhabiting the said coastline continue to practice some of the deep-rooted technologies, including boat building and exploitation of marine resources.
All the elements of material culture (artifacts, structures, and features; for a broader discussion see Wynne-Jones 2016) and their accompanying traditions have timelines extending up to about two millennia ago. Combined with the linguistic evidence (Nurse and Spear 1985) and oral traditions, they represent visible, invisible, tangible, and intangible evidence of complex local and global histories in Eastern Africa. Indeed, they are testimony of the expansion of coastal culture. The developments include the establishment of stone-built towns to serve as hubs of trade between the Indian Ocean and the interior of Africa in what is referred to as the “Swahili civilization.” Swahili civilization encompasses the local and global connections and trading activities that took place in Eastern Africa, attracting traders from the Middle East, the Indian subcontinent, and the Far East. The coastline upon which the mentioned evidence of global connections are found, is referred to as the “Swahili coast.” The Swahili civilization, therefore, refers to the social complexes, which developed in Eastern Africa over nearly two millennia and are marked by the material culture that signifies social and economic interactions between Eastern Africa and other parts of the world.
To be able to explain what this Swahili civilization is, our article is divided into six sections. The first section to this introduction, “Defining the Swahili,” explains who the Swahili are and what scholars have said about this group of people known in Eastern Africa as wa-Swahili. It is neither about the peopling nor the ethnic groups found in Eastern Africa but existing narratives on who the Swahili people are (for a broader discussion see Ray 2018). We then cover the coastal environment in which the Swahili civilization developed. In this section, “Environment of the Swahili Coast,” we aim to explain the contribution of environment, weather, and other natural factors that influenced what we today call the Swahili civilization. Subsequently, we present the elements of material culture found on the Swahili Coast that form what we consider to be the markers of Swahili civilization. This material evidence, which characterizes the Swahili civilization, includes ceramics and beads—both local and imported, monumental structures, maritime-based remains such as stone anchors and ballast, metallurgical assemblages, and glass. There are also narratives or oral traditions, the Swahili language, and the Islamic religion all of which facilitated the development of Swahili culture.
Defining the Swahili
Who are the Swahili? This has been a question of many researchers in Eastern Africa, and different views continue to emerge (e.g., see Ichumbaki 2017; Ray 2018). Prins (1965) in his study of maritime culture, or the relation between people and the sea, describes the maritime ethos of the Swahili people in Lamu. De Vere Allen (1993, 252–259) provides definitions of the Swahili as people who made their home around one of the traditional Muslim settlements of the East African coast or became Swahilized, so their lifestyle involves Swahili cultural features such as language, weddings, dress and mannerisms. For most of the 20th century, there was an assumption that a large part of the population of the East African coast descended from Arabia or Persia (Chittick 1961, 1; Kirkman 1963, 9). This conclusion originated from excavations of sites with monumental architecture containing Islamic elements and oral traditions that tell about the settlement of Persian merchants, including princes from Shiraz in seven towns along the coast (Horton and Middleton 2000, 46–47, 59). These narratives are supported in a 16th-century Portuguese document, wherein the Kilwa Chronicle is known to have been written down for the first time, and an Arabic version given to the British consul by Sultan Barghash in 1877. This 16th-century document maintains that seven ships came from Shiraz and stopped at Mandakha, Shaungu, Yanbu, Mombasa, Pemba, Kilwa, and Hanzaun (Coppola 2018, 148; Freeman-Grenville 1962a, 35). The probable basis for this argument is late 1st-millennium interactions between Shiraz and indigenous Africans evidenced in finds of blue-green glazed pottery and recorded in 10th-century writings of an Arab historian and geographer, Al-Masudi. The ships were followed by a southward movement of Muslims from the Lamu Archipelago around 1000 ce, bringing their coinage tradition and a local form of Islam. Another claim to justify that the Swahili are Shirazi is the assumption that Kiswahili, the language of the Swahili community, is a mixture of Bantu and Arabic (Horton 1996, 4).
However, interpretations of the origin of the Swahili people have been revised by more recent archaeological work from the late 20th century to early 21st century reporting coastal settlement prior the Arabic influence (Chami 2002a, 2–3; Horton 1996, 407). Furthermore, investigations extending the geographical coverage beyond the major settlements whose buildings were made up of coral stones (stone towns) have revealed areas of iron-working Swahili communities with little foreign influence and a relationship between later 1st-millennium ce coastal and local hinterland populations (Chami and Mapunda 1998; LaViolette et al. 1989, 1999; Pollard and Kinyera 2017). This argument is supported by linguistic evidence predating the 19th-century Omani settlement, when many Arabic words were introduced, showing that Kiswahili forms part of the North-East coastal Bantu language cluster. Kiswahili also shares many features in common with the Mijikenda and Pokomo languages of the immediate coastal hinterland from the Tana River in Kenya to northern Tanzania (Horton 1996, 4; Horton and Middleton 2000, 27).
A study led by Fleisher in 2015 has renewed controversy in investigating when the Swahili became a maritime society and refers to a dramatic transformation in coastal life in the early 2nd millennium ce. Supporting evidence for this argument comes from long-distance eastern African navigation leading to substantially increased wealth, which is reflected in coral and lime architecture. This identification depends on definition of the terms “maritime” and “Swahili.” The authors defined maritime to refer to the use of maritime space by boat, sailing routes, the gathering of sea resources, and topographical naming; and refer to the ancestors of the Swahili appearing in the 1st millennium ce.
Opposing views, by contrast, define “maritime” more broadly to cover all interactions with the sea, and that in order to better define who the Swahili are, one has to understand when settlement on the Swahili Coast began (e.g., see Ichumbaki 2017; Kusimba and Walz 2018). As there is enough evidence that people started to inhabit the Swahili Coast since the Neolithic period (Chami 2004a; Chami and Kwekason 2003), and it has never been abandoned, then, Ichumbaki (2017) argues, the Swahili people/society are inhabitants of the East African coast since about 20,000–30,000 years ago (Chami 2009a, 2009b, 2009c; Prendergast et al. 2016). Around the 9th century, several other human groups migrated to the Swahili Coast, forming a mixture of the Swahili descendants and “migrants” from different parts of the Indian Ocean worlds (Ichumbaki 2017, 2). Furthermore, the communities themselves who lived on the coast did not begin identifying themselves as Swahili until the 19th century. This observation means that further understanding of how eastern Africans identified themselves in earlier eras is needed (Ray 2018, 67, 76).
Environment of the Swahili Coast
The Swahili have occupied a coastal environment shaped by Pleistocene and Holocene sea level changes evidenced by raised coral terraces, with caves such as Kuumbi and Mwanampambe Caves on Unguja and Tung’ande and Kisima Kissongo Caves to the south of Kilwa, as well as drowned estuaries or rias such as Lamu, Mombasa, and Kilwa. Sand deposition around river mouths has allowed the growth of beach ridges such as at Mkadini to the north of the Ruvu River, and vegetated spits have provided sites for Swahili towns inland from the sea such as the late medieval Kaole ruins (figure 2). Conversely, an intertidal mosque among mangroves at Songo Mnara (figure 3) may be due to erosion of the shoreline or sea level change.
During the months of November to March, the prevailing trade wind is the northeast monsoon with steady and light winds (figure 1). The southeast monsoon extends from May to October with strong winds (Richmond 1997, 8). This seasonal reversal of monsoon winds has allowed the transit back and forth by sailing ships within a year in the western Indian Ocean for at least 2,000 years. The ability of merchants to anticipate the monsoon, and so arrange the shipping of cargoes with confidence, permitted the organization of marketing and finance. In turn, this allowed growth of stable settlements and accumulation of wealth, including investment in permanent residences and in civic and religious buildings (Kusimba 1999, 69).
The Swahili Coast’s forests provide game meat, charcoal, firewood, timber, medicinal plants, honey, mushrooms, and fruits (Dharani 2002). Important trees are the baobab. Long living and commonly found associated with archaeological sites and modern settlements, the baobab provides food from its seed, red dye from roots, shelter from branches, and medicinal qualities (Ichumbaki 2015). African ebony or blackwood has a valuable and durable purplish black timber; the walking palm is used for thatching, weaving baskets, and mats; and the casuarina (or whistling pine) is used for dhow masts and poles, while is bark contains tannin and yields a red dye. Coconut palm plantations are common, with many uses including food, timber, oil, and rope. The largest expanses of mangrove forest are found in estuaries, deltas, and sheltered bays. For the production of sea salt, important for preserving fish, saltpans are often seen today, located in or behind mangrove forests.
The intertidal lagoons and reef flats contain fish, shellfish, echinoderms, and crustaceans. Methods of fishing include fish trap fences and baskets along with baited hook and line from dugout canoes and small dhows. Living shallow water corals and limestone from the raised Pleistocene reefs can be used as building blocks and lime making (Richmond 1997, 21). Porites coral is fine-grained coral cut from a living reef, allowing carving and shaping before it hardens (Horton 1991; La Violette 1996, 76). The lime mixed with water can be used as whitewash, and when mixed with sand or earth can form a mortar for building. The production of lime involves the collection of living corals, limestone, and mollusk shells for sources of calcium carbonate.
Generally, one can argue that the nature of the environment and people’s effective exploitation of the available resources shaped one another and contributed greatly in sustaining the achieved civilisation. The monsoon winds facilitated navigation and linked east Africa with other parts of the Indian Ocean world, hence, developing a broader form of international trade or globalization. Exploitation of mangrove resources and coral stones enabled the Swahili to easily obtain building materials for the construction of stone monuments that are scattered along the coast. Tapping the seawater to produce salt at saltpans, for example, at Mkadini (Chittick 1975) and Nunge (Kessy 2019a), enabled the Swahili not only to add flavor to their unique cuisine but also gave them opportunity to exchange salt with other goods needed on the Swahili Coast. Likewise, the nutrient-rich alluvial soil deposited by river flooding facilitated agricultural activities and ensured communities obtained sufficient nourishment. Indeed, it was this environmental advantage that acted as a catalyst in facilitating social and economic developments, hence, civilization. That is, the environment of the coast of Eastern Africa served as a kernel upon which global connection, building of complex monuments, optimal exploitation of available resources, and religious beliefs arose (for further discussion see Kusimba 2018).
Pre- and Early Iron Age on the Swahili Coast
Occasional references to Stone Age communities along the coast of East Africa were made in the latter half of the 20th century (e.g., see Gramly 1981; Harding 1961; Isaac 1974), but it was not until the first decade of the 21st century when scholars fully accepted the presence of such human habitation. The major reason for this acceptance is the continued reporting of various sites with stone tools, many of which indicate resource exploitation and mastery of the coastal environment between 30,000 and 20,000 BP (Chami 2009a; Kessy 2009a, 2009b, 2010, 2019b; Prendergast et al. 2016). For example, during the Stone Age period, coastal communities imported volcanic stone (from either Kilimanjaro or Comoro Island) for artifact making in the Kuumbi cave on Unguja (Kessy 2010, 53). If sea level rise after the last Ice Age had made Unguja Island when these artifacts were imported, then, this is a reflection of interactions between and among the island dwellers as well as coastal and mainland communities. An importation of stone from the mainland to the island was accompanied by exchange of other materials such as beads made of faience and carnelian materials and cowry shells (Leakey 1966; Sassoon 1968). Ichumbaki (2017, 5) argues that although the source of carnelian and faience-made beads is uncertain (as their origin could either be North Africa, Asia, or both), those made of cowry shells originated from the coast of the Indian Ocean, certainly along the present-day coast of Kenya and/or Tanzania. Indeed, it was these Stone Age communities that set foundations for the Iron Age and subsequent Swahili civilization.
In Eastern Africa, the early Iron Age (EIA) is associated with the spread of Bantu languages, crop cultivation, herding of domestic animals, and metallurgy (Phillipson 1977, 210, 2002, 188, 198). The people farmed either sheep or goats, sorghum and millet, and settled in permanent or semi-permanent villages (Horton and Middleton 2000, 26). The associated beveled and thickened pottery has been termed Kwale Ware or Early Iron Ware (EIW) (Fleisher and Wynne-Jones 2011; Soper 1971). Iron working was necessary for the manufacture of a variety of tools indispensable to clearing and farming African soils, and knowledge of the chemical process for transforming base materials enabled smiths to achieve high status (Kusimba 1999, 101). Discoveries on Mafia, Koma, and Kwale Islands indicate early farmers had a maritime technology to access the islands and would have been able to travel by boat along the coast, allowing for the rapid spread southwards of EIA groups (Chami and Msemwa 1997, 52; Horton and Middleton 2000, 38).
Occupation and trade on the Swahili Coast at this period is supported by classical documents from around the 1st and 2nd centuries. Documents including Periplus Maris Erythraei and Geographia describe several ports down the East African coast, including Rhapta, but its location has not been definitively identified (Freeman-Grenville 1962a, 3; Horton and Middleton 2000, 33, 36). The Periplus was written by an Egyptian Greek merchant and gives trading information with the general direction and length of the sailing course. However, the information provided by this document is limited, for the author was mostly interested in luxury goods for the Mediterranean World (Casson 1989, 7–8, 15). The information contained in these classical documents explain that exports from Rhapta were ivory, rhinoceroses’ horn, and tortoise and nautilus shell. The imports included spears, axes, knives, awls, glass stones, wine, and grain (Casson 1989, 61; Horton and Middleton 2000, 37).
Despite this historical evidence, classical finds along the East African coast are rare compared with later 1st-millennium finds, probably due to the concentration of study around stone towns, which appear to have been founded in the 7th to 8th centuries. With the exception of four beads that Felix Chami (1999, 239) interpreted as “Roman,” but which attribution has however been questioned (Wood 2011, 24–25), there are few cultural materials predating the 7th century. Horton and Middleton (2000, 37) explain the deficiency of classical finds to be due to most East African commerce being in the hands of Arabian traders who could complete the return journey within the year, whereas ships coming from the Red Sea took fifteen months. Examples of EIA sites include Kivinja, 20 km north of the Rufiji Delta, which has been dated to 90 ± 60 bce (Kusimba 1999, 91), and has possible Greco-Roman glass and alkaline-glazed pottery (Horton and Middleton 2000, 38). A cave on Juani Island in the Mafia Archipelago produced an “eye” bead and a mosaic bead from Rhodes dating from 300 bce to 400 ce and red ware possibly of Roman origin associated with local potsherds of 3rd century ce (Chami 2002b, 40–41, 2004b, 99, 2004c), but the authenticity of all this evidence remains questionable (Wood 2018, 459). Some uncertainty has been associated with the finds due to stratigraphic and chronometric affiliations (Boivin and Crowther 2018, 107). Mlongo, on Mafia Island, which has been dated to c. 250–500 ce, contained an Indo-Pacific glass bead and carbonized palm fronds, possibly from the Southeast Asian coconut, which links to one of the East African trade items mentioned in the Periplus (Horton and Chami 2018, 139).
In the late 6th century, Sasanians based in the Persian Gulf started to dominate the trade. The site of Fukuchani on Unguja contained some imported ceramic, which was very similar to the Persian Gulf and Indian earthenware storage jars found at Ras Hafun near the Horn of Africa (Horton and Middleton 2000, 32, 43, 72). Red ware, green/yellow, and other imported potsherds were found in the EIW horizon in the Kuumbi cave in Zanzibar (Chami 2002b, 40), of which several red ware fragments, one of a rim and neck of a vase, were also similar to potsherds recovered from Ras Hafun (Chami 2002b, 41). At Unguja Ukuu, North African red slip pottery and alabaster from Egypt was dated to the 5th to 6th centuries ce (Horton and Middleton 2000, 32). The first Asian fauna and crops including chicken, black rat, rice, mungbean, wheat, and cotton appear during this period (Boivin and Crowther 2018, 107).
From the foregoing discussion it is apparent that communities that lived at the coastline of Eastern Africa had interactions with other communities from hinterland Africa (Pawlowicz 2013) as well as other parts of the Indian Ocean world such as China (Ichumbaki 2020). The presence of material culture that originated from outside the region as well as the firmness and quality of locally produced cultural objects are evidence of the sociocultural and economic developments that took place over time. These initial developments set strong foundations for the more advanced global connections (part of the Swahili civilization), which we discuss in the following sections, “Early Medieval Growth in Trade” and “Late Medieval Urbanization.”
Early Medieval Growth in Trade
The later 1st millennium ce was the beginning of permanent iron-using settlements. The appearance of a new type of pottery, found below the stone towns throughout the East African coast, such as Kilwa Kisiwani, suggests close contacts (Kusimba 1999, 93). This pottery was described from excavations at Shanga in the Lamu Archipelago where it dated as early as c. 750 ce and was named Early Tana Tradition (ETT). The same pottery on the Tanzanian coast dates c. 700 ce and has been named as Triangular Incised Ware (TIW; see figure 4a and 4b) after a common triangle-like decoration (Chami 1994; Horton 1996, 243; Horton and Chami 2018, 140). This earthenware is uniform in decorative style, being found as far south as the Comoro Islands and Mozambique (Pollard et al. 2018, 452; Pollard and Kinyera 2017, 930).
Descriptions of the early East African coastal people in the classical documents and the similarity in cooking vessels found at early coastal sites and at Cushitic-speaking pastoralists and hunter gatherers from the coastal hinterland led to suggestions that the origin of ETT was in the Pastoral Neolithic wares of the Rift Valley of Kenya (Horton 1996, 411; Kusimba 1999, 108). Another pattern was identified linking ETT spatially with the northeast coastal Bantu speakers; it is also present at Kaya Shingwaya, an early “traditional site” of the Mijikenda (Horton and Middleton 2000, 42). Against that, TIW has been considered to develop from EIW in Tanzania because of similar decorations and thickening of the rims and the presence in stratigraphic sequence at Nkukutu and Kivinja sites in the Rufiji Delta (Chami 1994, 69, 73, 1998, 201–202).
Similar ceramics with TIW decorations of punctates, zigzag lines, and arc lines of shell impressions are found at Comoros, though Chantal Radimilahy says TIW was not observed in her excavations at Mahilaka on Madagascar (Radimilahy 1998, 201–202). Henry Wright has speculated that the differences could be due to Austronesian colonists on Madagascar mingling with Swahili-speaking people (Wright 1993, 664–65). An interesting discovery of black volcanic basalt on the coral limestone reef outside Kilwa Kisiwani Harbor has been interpreted as the ballast of a shipwreck (Pollard 2008a, 110; Pollard et al. 2016, 357–360). Among the basalt were twenty sherds of unglazed Siraf storage jars. The combination of basalt ballast with the pottery shows a late 1st-millennium sailing route that passed Kilwa, perhaps returning from the volcanic Comoros (Pollard et al. 2016).
TIW sites often comprise up to 5% imported pottery appearing with a consistency indicative of purposeful contact with foreign traders (Kusimba 1999, 97, 100). One of the commonest types of imported pottery around the Indian Ocean from the 7th to the 10th century was a large green glazed jar commonly known as blue-green glazed ware from the Persian Gulf (figure 5). Some economic and social variation can be identified in differential access to imports along the coast, as seen in the difference between the Bagamoyo and Kilwa areas of Tanzania. The Bagamoyo area on the western side of the Zanzibar Channel has at least four 7th- to 10th-century sites with imported ceramics in a 16 km stretch of coastline including Mkadini, Maganbani, Kaole Village and Kaole Hill (Chittick 1975, 151–153; Chami 1994, 57, 91; Pollard and Kinyera 2017, 927). Foreign artifacts include fragments of blue-green glazed pottery, Siraf storage jars, and clear to green glass. There are also examples of pottery and beads from the Far East. The local artifacts included an iron nail, bead grinders, iron slag, and shellfish, turtle, fish, and animal bones, indicating a market with both production and trade activities. This combined evidence from around Kaole provides strong evidence for the location of an important trading port during the 1st millennium.
The greater evidence of trade in the Bagamoyo area contrasts with late 1st-millennium Kilwa Kisiwani, which lies approximately 350 km south of Kaole. The modern village of Kilwa Kisiwani is located on the same site as the ancient town of Kilwa: it is sited at the northwestern end of the island opposite the present administrative area of Kilwa Masoko on the mainland (figure 6). On the coast of Kilwa Masoko, there is another late 1st-millennium ce site contemporary with the foundation of Kilwa at Mso Bay. Neville Chittick’s excavations on the island indicated limited external trade in the late 1st-millennium ce, through the presence of a few sherds of Islamic pottery and glass, glass beads, and carnelian beads.1 The Mso Bay site had similar local artifacts to that around Bagamoyo, including iron slag, fish bone, and evidence of buildings in the form of post holes and daub.
However, during the late 1st millennium, fish bones at Mso Bay were few compared with Kaole Village where 366 bones were counted in a much smaller area of excavation. Low seafood in the diet suggests less activity directed toward the sea compared with the Bagamoyo area. The imported artefacts and seafood evidence suggests more foreign trade and maritime activity in Bagamoyo compared with Kilwa, especially during the early medieval period. An important further difference with Bagamoyo is the presence of 1,019 stone flakes and debitage, and hammerstones at Mso Bay. At Kaole Village neither flakes nor débitage were found. Below the stone town on Kilwa Kisiwani, only one quartz flake and two other fragments of quartz were recorded in excavated deposits, suggesting further local variations in different groups or activities. In Bagamoyo, the evidence for stone- and iron-using communities living in close contact come from Kiwangwa (about 25 km landward) where significant amounts of stone tools have been reported (Kessy 2019b).
Additionally, despite the high level of industrial activity, Mso Bay resembles Kilwa Kisiwani in having few imports, which contrasts to the foreign trade markers identifiable at Bagamoyo. In Mso Bay, only two blue-green glazed sherds, one lead-glazed polychrome sherd, and a blue-glass fused bead was found and identified. Overall, it is considered that the balance of evidence points to the simultaneous existence of two groups living in close spatial proximity around Kilwa. Such a scenario is similar to that of Shanga where a multiethnic society was recognizable during the 1st millennium ce but different from that of the coast around the Zanzibar Channel, showing more ethnic homogeneity at that time. The evidence suggests that Mso Bay was almost exclusively involved with farming and the iron industry, trading locally with Stone Age groups, but had more limited engagement in maritime activity and sea communications than that at Kaole Village.
These pieces of evidence for trade are associated with the industrial activity marked by “bead grinders” that have been found in association with TIW sites consisting of single or multiple grooves (Flexner et al. 2008). The grooves are parallel, right angled, and diagonal across material made from local pottery, imported unglazed storage pottery, and stone. Their purpose is not very clear though they were probably largely used for making shell beads. Also, they seem to have been suitable for grinding stone beads for which the harder quartz and river pebbles were probably used. The grinder (figure 7) may also have been used for rubbing sherds (pottery rubbed into disks), making spindle whorls (Horton 1996, 327, 342), or to sharpen combs (Chittick 1984, 156).
Over a hundred bead grinders, 761 shell beads including unfinished beads, along with land and seashells, were recovered from Kaole Village, indicating they were being manufactured on site. The bead grinders are grooved objects made from local pottery, imported pottery, limestone, and sandstone, but also the softer materials of mortar and daub. The evidence suggests intensive bead making on site, and a local industry stimulated by the importance of beads to the local economy and trade. The beads may have been used in exchange for animal products coming from the hinterland.
The book Yu-yang-tsa-tsu by the Chinese scholar Tuan Ch’eng-shih, who died in 863 ce, reported exports from the East African coast to have been ivory, ambergris, and slaves and that East Africans traded with Persians, probably for cloth—Arab travelers reportedly raided the East African coast for such cloth (Freeman-Grenville 1962b, 37). Ibn Lakis recorded an attempted storming of Kanbalu by a Waqwaq fleet eager to gain access to its supplies of slaves and other goods in the 10th century (Shepherd 1982, 137). Archaeological evidence for this human trade from the Lamu Archipelago includes a chain link and two possible irons at Shanga and three rings from Manda (Horton and Middleton 2000, 75).
South of Kilwa, there are again differences in access to imports evidenced in archaeological excavations, as glass beads and glass fragments are rare in the Comoros and Madagascar, whereas imported ceramics, mostly from the Near East, make up 4% of all sherds, indicating there was substantial contact with Indian Ocean traders (Wood 2011, 26). During the 15th and 16th centuries, Chibuene, in Mozambique, was where inland trade routes for gold and ivory departed from the coast. This would explain the nearly 2,000 glass beads found there, as they could have been used for trade inland (Ekblom and Sinclair 2018; Wood 2011).
From the 8th century there is evidence of Islam in the form of burials and timber buildings below later stone mosques at Shanga, Ras Mkumbuu on Pemba Island, and Comoros (Horton 2018, 487–488). Conversion to Islam would have conveyed economic and social advantages including a close association with Islamic merchants from the Middle East. It also provided opportunities for African Muslims to travel freely abroad for commerce, education and pilgrimage, and the strengthening of trust between trading partners through the adherence to a common faith (Kusimba 1999, 133–134).
The foregoing discussion shows that the sociocultural and economic developments that occurred during the pre- and early Iron Age periods did not end during the 1st millennium ce. Instead, these developments were foundations for the industrial, trading and maritime activities recorded from various coastal sites dated between the 7th and 10th centuries. Locally initiated industrial developments marked the making of TIW/ETT and (bead) grinders, global maritime trade, or connections marked by both imports (blue-green glazed wares) and exports (ivory and ambergris), while commitment to an Islamic faith was influential in building what we all celebrate as “Swahili civilization.” In the next section, “Late Medieval Urbanization,” we explain what followed building on this strong foundation during the Iron Age and early medieval period.
Late Medieval Urbanization
We have already documented that during the 7th and 10th century, there were notable local industries and trade connections. These developments grew significantly between the 10th and 15th century. The evidence for the remarkable growth included building of stone towns as well as an increase in maritime trade. We will now provide further details on what happened during this period alongside the contributions to building the Swahili civilization.
Mark Horton (1996, 399) records a new building technique using Porites coral from the early 10th century at Shanga. While the technique of construction could have been introduced from elsewhere in the region, the architectural form remained the same with a timber hall and mosque replaced in coral. Many of the earlier settlements were abandoned around this time, such as Tumbe on Pemba Island (LaViolette, 2018), or shifted location due to changing geomorphology of the coast from river deposition and accretion, for example, around Bagamoyo at Kaole and Mkadini. Other settlements developed into dominant city states such as Manda and Kilwa, the latter having territory to surrounding islands such as Mafia (Pollard and Ichumbaki 2017, 474–475). Industrial activities, evidenced from cooking ovens, iron slag, pottery crucibles, spindle whorls, and coins suggest farmers and tradesmen created surpluses for expanding local and regional commerce (Harding 1960, 136; Kusimba 1999, 36–37, 125). Furthermore, indigenous coastal trade can be seen from Madagascar’s export of soapstone vessels (Shepherd 1982, 138) and schist for reworking in the northern towns (Horton and Middleton 2000, 95).
Changes in imported pottery at Manda show a decrease from the late 1st millennium with around 23% blue-green glazed ceramics, mostly jars, to 15% sgraffiato, mostly bowls, by mid 11th to late 12th century (Chittick 1984, 66, 71, 79, 225). Different African towns favored Gulf, Indian, or southern Arabian trade connections, for example, at Ungwana, on the Tana Delta, there was a larger import of sgraffiato than at Gedi (Kirkman 1966, 38). Spatial differences along the Swahili Coast in the 11th to the 13th century can be seen in the local pottery to the north of Tanga, named by Horton (1996) as “Mature Tana Tradition,” diverging from the southern coasts. The southern coast had a tradition known as Plain Ware (Chami 1998, 211) dating from the 10th to 13th centuries (Chami 1999, 1), also known to Chittick (1974) in Kilwa as Early Kitchen Ware Type 2.
Between the 13th and 15th century, the more varied local pottery in Tanzania has been termed as neck-punctated or Swahili Ware pottery (Chami 1998, 212, 1999, 1, 2002c, 46). Neville Chittick (1974) included red painted ware, Husuni modeled ware, and Wealed ware for the pottery in his excavations in Kilwa Kisiwani for the 14th to 16th centuries. The changes in style of local pottery (Kirkman 1966, 18, 24) suggest an emergence of professionalization of crafts and demographic changes in local taste coinciding with the influx of new people to the coast (Kusimba 1999, 38, 127).
During the 14th to 16th centuries, the volume of locally produced iron slag and spindle whorls decreased, suggesting declining industrial activity, perhaps because imports of iron and cloth from the interior or across the Indian Ocean were cheaper (Horton and Middleton 2000, 82; Kusimba 1999, 37–38). At Ungwana, bowls with bases, beakers, and drinking cups reflect a rising standard of living in the late 14th and 15th century (Kirkman 1966, 24). Accompanying this, there was an increase in size and elaboration of stone houses and domestic architecture, and the volume of imported ceramics, especially from China, expanded (Kusimba 1999, 37). The discovery of Ming Yongle (1403–1424 ce) imperial kiln blue and white porcelain and Hongwu (1368–1398 ce) Longquan official kiln porcelain, which were made exclusively for the imperial family or central government, at Mambrui to the north of Malindi, have been interpreted as gifts from the 15th-century Zheng He’s fleet (Qin and Ding 2018, 208–10). Porcelain as an important symbol of status goes back to the imported Chinese and Islamic display ceramics of the 9th century and, from the 13th century, porcelain was used to decorate the tombs of patricians (Horton and Middleton 2000, 82). As towns grew in size, they attracted migrants: the increased use of serving bowls suggests migrant households and changes in table etiquette or introduction of rice as a food staple (Kusimba 1999, 130).
During the 13th and 14th century, Kilwa became an international cosmopolitan trading entrepôt, as it was in a strategic position to participate, manage, and control much of African trade between Sofala to the south and ports along the northern Swahili Coast (Kusimba 1999, 38). The control of Sofala was important as gold from the Zimbabwe plateau into the world trading system was channeled through there (Sutton 1998, 113). At Kilwa, increased commerce and wealth was reflected in extension of the Great Mosque (figure 8), the Great House that could have been used by pilgrims, and possible caravanserai of Husuni Ndogo, a large enclosed space where trade goods could have been stored. The architectural signs of an economy focused on Indian Ocean trade appear with stone mosques overlooking the harbors and landing places such as Malindi Mosque on Kilwa Kisiwani Port and the Necropolis Mosque of nearby Songo Mnara. Even intertidal areas sport mosques such as again at Songo Mnara, while the ports around Kilwa have sea walls, steps, and walkways (Pollard et al. 2012, 52).
During this peak period of commercial activity, some stone structures were built outside the main settlements such as the sultan’s palace of Husuni Kubwa (figure 9) in around the early 14th century, situated to offer a commanding harbor view. Additionally, on this stretch of coast are the reef coral causeways across the lagoon and platforms on the fringing reef crest that together mark the entrance to harbors around Kilwa Kisiwani (Pollard, 2008a). Associated with this complex are three mosques overlooking landing places and surrounding pottery that suggests late 13th to 14th century activity (Pollard 2008b, 276–277). It is possible that the reef coral material may originally have been naturally deposited in a rare event such as a cyclone, but these features appear to have been artificially straightened and raised in some instances for the purpose of aiding navigation, while incidentally allowing access to the reef for marine resources such as shellfish and stores of coral for lime making (Pollard 2018, 45–46; Pollard et al. 2012, 51).
Oral tradition links Angoche in Mozambique with Kilwa, and it was probably part of the journey to Sofala. Duarte Barbosa, in the early 16th century, recorded Angoche as a center for exchange of gold, copper, silver, iron, ivory, leather, and slaves for cotton, silk, and beads (Kusimba 1999, 135–136). Angoche provides evidence of Swahili civilization from the 1st millennium with the presence of TIW fragments and a bead grinder but few trade artifacts. However, artifacts from the 13th to 16th centuries, including Husuni Modeled Ware, are similar to those found around Kilwa. These dates correspond with a shift in location of sites to sand spits and inlet mouths that have easy access to deep channels for larger oceanic vessels to land and are also important in the context of crossing the Mozambique Channel. The sandy coast in Mozambique around Angoche resulted in most houses probably being wattle and daub so that traces of limestone or reef coral houses are rare. However, reef coral gravestones are relatively common, no doubt traded with the Swahili settlements further north from around Ilha de Mozambique where limestone can be sourced.
In the 21st century, mangrove poles are still being gathered at landing places for export to the limestone coast to the north, and this was probably an ancient tradition. There are similarities in local and imported pottery found further north at Kilwa and Lamu Archipelago and south around Sofala from this period. The Husuni modeled ware is particularly diagnostic to the late 13th to 14th centuries at Kilwa, showing that Angoche lay on the route from Kilwa to Sofala. The similarity in artifacts with Kilwa suggests Angoche was under the influence of this entrepôt at this time.
The Swahili During the Colonial Period
Vibrant developmental initiatives and many sociocultural and economic building projects, including those initiated between the 12th and 15th centuries ce, at some Swahili coastal towns declined significantly beginning the 16th century. From the mid 2nd millennium ce, some centers with marked Swahili civilization were significantly altered in character by construction of forts for housing Portuguese garrisons. These forts are still notable at the towns of Mozambique Island, Kilwa Kisiwani, Mafia, Zanzibar, Malindi, and Mombasa. Whereas the Portuguese built several strongholds in Mozambique, there was a limited scale of their (Portuguese) activities along the Kenyan and Tanzanian coasts. The principal fort in the north was Fort Jesus in Mombasa completed in 1593, but Kilwa had one of the earliest fort built in 1505 (Croucher 2014, 36). Outside the fortification activities, the Portuguese also built churches, custom houses, and remembrance pillars (Bennet 1978, 9; Clark and Horton 1985, 13; Gray 1962, 39). In Zanzibar, for example, Portuguese activities are marked by the presence of a major church and factory underlaying what is now known as the Omani fort in Unguja. This Portuguese colonialism did affect activities by local people and Arab merchants who were mostly benefiting from the Islamic trading system (Omulokoli 2006, 146–148).
The loss of Portuguese control on the East African coast started in 1696 when local Swahili allied with Oman and successfully laid siege to Fort Jesus. Between 1726 and 1728 Portuguese rule finally ended after several comeback attempts, and power shifted to the Omani sultanate based in Zanzibar (Croucher 2014, 36; Sheriff 1987). By establishing Zanzibar as his main residence in the 1840s, Sayyid Said, the Omani ruler (and later Sultan of Zanzibar), managed to bring the mainland coast under his control. It should, however, be noted that during the 17th and 18th century, coastal towns including Tanga, Mtangata, Pangani, and Bagamoyo shared an independent system of authority, despite Portuguese and Omani presence in major coastal towns (Allen 1993, 200; Middleton 1992, 42). Each settlement on the Tanganyika/Tanzania central and northern coast was under a local African chief (jumbe), who by lineage or marriage ties was connected to the ruler of the neighboring town (Chande 1991, 22). During this period no attempt was made by either the Portuguese or the Omani to change the confederation of the Tanganyika/Tanzania central and northern coast with its established rule of local chiefs. However, by the 1870s the Sultan of Zanzibar installed governors (liwali) in each coast town. Unfortunately, the appointed governors compromised the indigenous political system by forcing local chiefs (jumbes) to work not for the benefits of their people, but for the Sultan of Zanzibar’s interests (Chande 1991, 29). The Portuguese and [Oman] Sultanate in Zanzibar, together with European colonialism, drew a line marking major changes in the Swahili civilization.
Internally and externally influenced developments including industrial, trade, and maritime-based activities along the coast of Eastern Africa are as old as the 1st century ce. Long-distance trading activities including encounters with Greco-Romans, Persians, Chinese, Indians, and Arabs happened between the 1st and 15th centuries ce. Around the 10th century the contacts became very intensive, leading to the growth of urbanism on the coast of Eastern Africa. These locally initiated developments combined together with externally influenced growth resulted in a unique culture generally named Swahili civilization. This culture existed, progressed, and flourished for nearly one and half millennia. However, encounters between Portuguese and the Swahili under their local rulers from 1498 onward at the Swahili towns of Kilwa, Tongoni, Mombasa, and Malindi did, unfortunately, put an end to that development. Although there were building initiatives, especially by the Omanis, these efforts lasted for almost a century before a decline in prosperity returned. Since then, what existed as the Swahili towns turned into monumental ruins, some of which have deteriorated beyond repair.
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