How did the Akkadian and Old Babylonian empires develop in Mesopotamia?

The wealth of Sumerian cities also attracted non-Sumerian conquerors from the north, beginning with the Akkadians and then the Babylonians. Both of these peoples created large states in the valley of the Tigris and Euphrates. Hammurabi, one ruler of Babylon, proclaimed an extensive law code. Merchants traveled throughout the Fertile Crescent and beyond, carrying products and facilitating cultural exchange.