Summary

Triumphal arch is the term generally used for an honorific arch (fornix, arcus; ἁψίς, πύλη), one of the most identifiably Roman of building forms. The descriptor is misleading: while arches frequently commemorated military achievements, not all can be linked with triumphs. These memorials also marked the territorial boundaries of cities and provinces, celebrated infrastructure projects such as roads and harbours, and memorialized the achievements of ambitious individuals. Votive associations with temples have been postulated but generally discounted. Simple in form, with one or more arched openings for passage flanked by sturdy piers and topped with a large attic, the honorific arch offered ample space for reliefs, sculptures, and inscriptions conveying directed messages with many, but not all, tied to military achievements. Honorific arches first appeared at Rome in the form of fornices connected with successful generals. Renamed arcus under Augustus, they were applied to the promotion of state values and military expansion as well as the accomplishments of the imperial family. Civic and private examples proliferated, as did particular architectural features: more openings for pedestrian traffic, more lavish embellishments, and a greater range of sizes. Spreading first through Italy, Gaul, and Spain, the form ultimately appeared in every Roman province. Honorific arches were especially popular in North Africa and the eastern provinces, where they served as gates and enriched the experience of urban streets. Punctuating highways in the countryside and harbour works at the shores, arches both explicitly marked regional boundaries and emphasized the Roman ordering of territory and peoples.