[2] The Third Dynasty of Ur immediately preceded the Isin-Larsa period, and its fall was due to the combined attacks of the Amorites from the west, and the Elamites from the east.

The last king of the Ur III dynasty, Ibbi-Sin, lacked the resources and the organized government needed to expel the Elamite invaders.

This gave the Isin dynasty control over the culturally significant cities of Ur, Uruk, and the spiritual center of Nippur.

The centralized political structure of Ur III was largely continued, with Isin's rulers appointing governors and other local officials to carry out their will in the provinces.

One such governor was an Amorite named Gungunum, who eventually broke with Isin and established his own independent dynasty in Larsa.

The exact events surrounding Isin's disintegration as a kingdom are mostly unknown, but some evidence can be pieced together from the historical and archaeological record.

Around 1860 BCE, an outsider named Enlil-bani seized the throne of Isin, ending the hereditary dynasty established by Ishbi-Erra over 150 years earlier.

[5] Hammurabi of Babylon founded the First Babylonian dynasty and united the whole region, after defeating the city of Larsa in 1763 BCE, as well as Eshnunna and Mari.