Shut up and take back Celine Dion! All right, now let's move to the other side of Africa where there was an alternative model of civilizational development. The eastern coast of Africa saw the rise of what historians call Swahili civilization, which was not an empire or a kingdom, but a collection of city-states like Zanzibar and Mombasa and Mogadishu, all of which formed a network of trade ports. There was no central authority. Each of these cities was autonomously ruled, usually, although not always by a king. But there were three things that linked the city-states such that we consider them a common culture. Language, trade, and religion.