Humans first settled in Mesopotamia in the Paleolithic era. By 14,000 B.C., people in the region lived in small settlements with circular houses.
Five thousand years later, these houses formed farming communities following the domestication of animals and the development of agriculture, most notably irrigation techniques that took advantage of the proximity of the Tigris and Euphrates rivers.
Agricultural progress was the work of the dominant Ubaid culture, which had absorbed the Halaf culture before it.