The Isin-Larsa period, spanning from approximately 2025 to 1763 BCE, represents a dynamic era in Mesopotamian history following the collapse of the Third Dynasty of Ur. This period is characterized by the political dominance of the city-states Isin and Larsa in southern Mesopotamia.

Isin emerged as a significant power under the rule of Ishbi-Erra, who founded its dynasty around 2025 BCE. He successfully liberated Isin from the control of the declining Ur III dynasty. Isin's prominence was marked by its leadership in restoring cultural and religious traditions, notably reviving the veneration of the moon god Nanna/Sin, an important deity in Sumerian religion.

The rulers of Isin, such as Lipit-Ishtar (1934-1924 BCE), are particularly noted for their contributions to the legal and administrative practices of the time. Lipit-Ishtar is credited with creating one of the earliest law codes, predating the famous Code of Hammurabi. These laws were instrumental in maintaining social order and justice in the rapidly evolving political landscape.

Parallel to Isin's rise, Larsa, another city-state, began to gain prominence under the Amorite dynasty. Larsa's ascendency is largely attributed to King Naplanum, who established its independent rule. However, it was under King Gungunum of Larsa (c. 1932-1906 BCE) that Larsa truly flourished, overtaking Isin in influence. Gungunum's reign was marked by significant territorial expansion and economic prosperity, largely due to the control of trade routes and agricultural resources.

The competition between Isin and Larsa for regional dominance defined much of the Isin-Larsa period. This rivalry manifested in frequent conflicts and shifting alliances with other Mesopotamian city-states and external powers like Elam.

In the latter part of the Isin-Larsa period, the balance of power shifted decisively in favor of Larsa under the rule of King Rim-Sin I (c. 1822-1763 BCE). His reign represented the zenith of Larsa's power. Rim-Sin I's military campaigns successfully subdued several neighboring city-states, including Isin itself, effectively bringing an end to the Isin dynasty.

Culturally, the Isin-Larsa period was marked by significant developments in art, literature, and architecture. There was a revival of Sumerian language and literature, as well as advancements in astronomical and mathematical knowledge. Temples and ziggurats constructed during this time reflect the architectural ingenuity of the era.

The end of the Isin-Larsa period was precipitated by the rise of Babylon under King Hammurabi. In 1763 BCE, Hammurabi conquered Larsa, thereby unifying southern Mesopotamia under his rule and marking the beginning of the Old Babylonian period. The fall of Larsa to Babylon represented not just a political shift but also a cultural and administrative transition, setting the stage for the further development of Mesopotamian civilization under the Babylonian Empire.