Our civilization is rooted in the forms and innovations of societies that flourished in the distant lands of Western Asia more than six thousand years ago. These earliest societies, established millennia before the Greco-Roman period, extended from Egypt to India. The earliest among them was the region known to the ancients as Mesopotamia, located between the Tigris and the Euphrates Rivers and occupying what is today Iraq, northeastern Syria, and southeastern Turkey. In Mesopotamia arose the first cities, believed by their inhabitants to be the property of the gods, who granted kings the power to bring prosperity to the people. Here urban institutions were invented and evolved. The need to record and manage the distribution and receipt of goods led to the invention of writing, monumental architecture in the form of temples, and palaces were created, and the visual arts flowered in the service of religion and royalty. These extraordinary innovations profoundly affected surrounding areas in Anatolia, Syria-Levant, Iran, and the Gulf, and Mesopotamia was in turn influenced by its neighbors. As Mesopotamia turned to outlying lands for such rare and precious materials as lapis lazuli, carnelian, diorite, gold, silver, and ivory, these regions were linked by networks of trade that encouraged cultural exchange.