He was the fifth king of the first dynasty of Babylonia, reigning c. 1748 to 1729 BCE.
His son Hammurabi greatly expanded the Babylonian kingdom.
Sin-Muballit succeeded Apil-Sin.
No inscriptions for either king are known.
In Sin-Muballit's 13th year, he repelled the army of Ur, which had invaded the territory of Babylon.
In the 17th year of his reign, Sin-Muballit took possession of the city of Isin and his power grew steadily over time as evidenced by his building and fortifying a number of fortresses.