Mesopotamia was located between the Tigris and Euphrates Rivers. Uruk was an important early city in Mesopotamia that had monumental temples called ziggurats. The priests initially held all the power because they controlled writing and record keeping, which not everyone could do. Over time, kings took on religious roles and overtook the priests' power, declaring themselves the new religious authorities. Some key inventions and developments that emerged from ancient Mesopotamia include cuneiform writing, the earliest form of taxation in the form of paying tribute to governments, and the establishment of one of the first empires in the region by the ruler Hammurabi of Babylon. The neo-Ass