The earliest history of Babylon is little known. Among the many cities flourishing in southern Iraq, the town first appears in texts in the third millennium BC. Until the last century of the third millennium, few references existed to Babylon; however, offerings made to the temple of Enlil in Nippur during this period (when Babylon was part of an empire ruled by Ur) suggest a city already of some size and wealth. From relative obscurity in the middle of the 18th century BC, Babylon emerged as the political center of southern Mesopotamia. It held this position almost continuously for the next 1,400 years.

Near Baghdad, around 85 kilometers south of the Euphrates, is the site of Babylon. The area is located north of the great alluvial plain of southern Iraq, a landscape of silts deposited by the Tigris and Euphrates into a vast rift created by tectonic movement as the Arabian plate slips beneath the neighboring Eurasian plate. In addition to defining modern-day Iraq's northern and eastern boundaries, the Taurus and Zagros mountain ranges were created by the same collision. As a result, Mesopotamia encompasses several environmental zones, but Babylon itself is found in the flat alluvial plain in southern Iraq.