Unfortunately the floodgates had opened. A few years later, a pretender calling himself Ilum-ma-ili, and claiming descent from the last king of Isin, raised another pan-Sumerian revolt. Samsu-iluna marched an army to Sumer, and the two met in a battle which proved indecisive; a second battle sometime later went Ilum-ma-ili's way, and in its aftermath, he founded the , which would remain in control of Sumer for the next 300 years. Samsu-iluna seems to have taken a defensive approach after this; in the 18th year of his reign, he saw to the rebuilding of 6 fortresses in the vicinity of , which might have been intended to keep that city under Babylonian control. Ultimately, this proved fruitless; by the time of Samsu-iluna's death, Nippur recognized Ilum-ma-ili as