They flourished from 3500 BCE onwards . They did not follow one another neatly - their periods overlap .
| City-state | From | Main city |
|---|---|---|
| Sumerian | 3500 BCE onwards | Ur, in Sumer |
| Akkadian | 2334 BCE | Akkad |
| Assyrian | 2154 BCE | Assur |
| Babylonian | 1900 BCE | Babylon |
Note the overlap. The Assyrians lasted till early 1700 BCE . The Babylonians rose from 1900 BCE onwards .
So for a time, the Assyrians ruled the north while Babylonia rose in the centre.
Let us learn about them one by one.