The use of numerical data and statistical sources in African history has expanded in recent decades, facilitated by technological advances and the digitization of primary sources. This expansion has included new analysis of traditional measures (population, government, and trade) as well as new sources of individual-level data such as census returns, marriage registers, and military and police records. Overall, this work has allowed for a more comprehensive quantitative picture of Africa’s history, and in particular facilitated comparisons within Africa and between African countries and other parts of the world. However, there remain misunderstandings about the collection, use, and interpretation of these data. Increasingly sophisticated methods of quantitative analysis can alienate scholars who have an intimate knowledge of the data and how they are produced, but lack specialist methodological training. At the same time, limited understanding of the origins and reliability of quantitative data can lead to misinterpretation.
Between 1800 and 1900, West Africa’s coastal states struggled to maintain autonomy in the face of imperial overtures from European trade partners. Simultaneously, these states coped with an overwhelming buildup of domestic slaves, some of whom rose to unprecedented higher political and economic positions. One particular individual, King Jaja of Opobo, came to the fore as an extreme example of how slaves became more capable of taking advantage of the changing political, religious, and economic landscape of the Eastern Niger Delta during this period. Born Mbanaso Ozurumba in the Igboland village of Umuduruoha in 1821, Jaja, as he would become known to his European trading partners, traversed the domestic slave systems of Southeastern Nigeria and arrived in the Delta trading state of Bonny in 1833. He obtained tremendous wealth and political influence through the burgeoning palm oil trade, ultimately becoming the head of one of Bonny’s most influential canoe-houses. Due to an internal dispute with a rival canoe-house in the late 1860s, Jaja removed his followers to a previously uninhabited island and cut off Bonny’s access to the lucrative interior oil markets. From 1871 on, Jaja monopolized the palm oil trade in the region to become the most influential trader from his new position as king of the island community, which he would name Opobo. However, by 1884, the relationship between Jaja and his British trade partners deteriorated, leading to Jaja’s exile in the West Indies. Political pressure forced the British to return Jaja to Opobo. Unfortunately, the once-powerful slave-turned-king died while trying to return home in 1891.