<P> The Sumerian city - states rose to power during the prehistoric Ubaid and Uruk periods . Sumerian written history reaches back to the 27th century BC and before , but the historical record remains obscure until the Early Dynastic III period , c. the 23rd century BC , when a now deciphered syllabary writing system was developed , which has allowed archaeologists to read contemporary records and inscriptions . Classical Sumer ends with the rise of the Akkadian Empire in the 23rd century BC . Following the Gutian period , there was a brief Sumerian Renaissance in the 21st century BC , cut short in the 20th century BC by invasions by the Amorites . The Amorite `` dynasty of Isin '' persisted until c. 1700 BC , when Mesopotamia was united under Babylonian rule . The Sumerians were eventually absorbed into the Akkadian ( Assyro - Babylonian ) population . </P>
when did the first city states arise in sumer
during the prehistoric Ubaid and Uruk periods