Another group of Semitic peoples had already begun to wander into Mesopotamia by then. These peoples, called the Amorites gradually took control of the region and founded a new Empire, often named after their capital, Babylon. Possibly the founder of the Babylonian Empire, and greatest Amorite leader was Hammurabi, who ruled from ca. 1792-1750 B.C.
Hammurabi conquered all of Mesopotamia and took the modest title “King of the Four Quarters of the Earth.” Hammurabi solved one of the perennial problems of rulership; how do you rule an empire? He appointed governors to rule in each of his cities. These governors represented the king, supervised in his name, and presided over the local courts. Hammurabi also created a single law code for his entire empire, providing a relatively stable and uniform system of law throughout his empire. The Amorite Empire lasted down to about 1650, when again, Mesopotamia fell to outside invaders. Weakened by a series of barbarian invasions, the great city-states fell in the mid-1500s B.C. to an Indo- European people called the Hittites. This very militant people who probably came from the Caspian region and had settled in Northern Asia Minor by 1650 B.C., created an empire that covered most of the Near East and flourished from 1400-1300 B.C.