In 1792 BC, an Amorite ruler named Hammurabi came to power in this state, and immediately set about building Babylon from a minor town into a major city, declaring himself its king. Hammurabi conquered the whole of southern and central Iraq, as well as Elam to the east and Mari to the west, then engaged in a protracted war with the Assyrian king Ishme-Dagan for domination of the region, creating the short-lived Babylonian Empire. He eventually prevailed over the successor of Ishme-Dagan and subjected Assyria and its Anatolian colonies. By the middle of the eighteenth century BC, the Sumerians had lost their cultural identity and ceased to exist as a distinct people. Genetic and cultural analysis indicates that the Marsh Arabs of southern Iraq are probably their most direct modern descendants.