Book excerpt: This Element discusses a medieval African urban society as a product of interactions among African communities who inhabited the region between 100 BCE and 500 CE. It deviates from standard approaches that credit urbanism and state in Africa to non-African agents. East Africa, then and now, was part of the broader world of the Indian Ocean. Globalism coincided with the political and economic transformations that occurred during the Tang-Sung-Yuan-Ming and Islamic Dynastic times, 600-1500 CE. Positioned as the gateway into and out of eastern Africa, the Swahili coast became a site through which people, inventions, and innovations bi-directionally migrated, were adopted, and evolved. Swahili peoples' agency and unique characteristics cannot be seen only through Islam's prism. Instead, their unique character is a consequence of social and economic interactions of actors along the coast, inland, and beyond the Indian Ocean.