themselves, may burst through their banks is never excluded. In 1831 the Tigris, rising suddenly, broke its embankment and destroyed 7000 houses in Baghdad in a single night.[89] Small wonder, then, that the boldness of those early people who undertook to found permanent settlements in the shifting plain had its obverse in anxiety; that the self-assertion which the city—its organization, its institutions, citizenship itself—implied was overshadowed by apprehension. The tension between courage and the awareness of man’s dependence on superhuman power found a precarious equilibrium in a peculiarly Mesopotamian conception. It was a conception which was elaborated in theology but which likewise informed the practical organization of society: the city was conceived to be ruled by a god. Theocracy, of course, was not peculiar to Mesopotamia: Egypt, too, was ruled by a god. But this god was incarnate in Pharaoh; and whatever may be paradoxical in a belief in the divinity of kings, it at least leaves no doubt as to the ultimate authority in the state and subjects the people unreservedly to the ruler’s command. In Mesopotamia no god was identified with the mortal head of the state. The world of the gods and the world of men were incommensurate. Nevertheless, a god was supposed to own the city and its people. The temple was called the god’s house; and it functioned actually as the manor-house on an estate, with the community labouring in its service. We shall describe the organization of the temple community at the end of this chapter. It is necessary first to survey the actual remains of the Protoliterate cities—the earliest cities in Mesopotamia.