What is "sin-muballit"

Sin-Muballit was the father of Hammurabi and the fifth Amorite king of the first dynasty (the Amorite Dynasty) of Babylonia, reigning c. 1748 to 1729 BC. He ruled over a relatively new and minor kingdom; however, he was the first ruler of Babylon to actually declare himself king of the city, and the first to expand the territory ruled by the city, and his son greatly expanded the Babylonian kingdom into the short lived Babylonian Empire.