Sardur built a fortress of huge stones west of the Rock of Van, and Ispuinis, his son and successor, chose that rock as his residence and as the holy seat of the god Khaldis. Ispuinis was a contemporary of Adadnirari IV of Assyria, son of Shalmanaserº and husband of Queen Shammuramat (Semiramis). Ispuinis fought and defeated his powerful rival, and was thus enabled to found a Khaldian colony at Musasir, west of the Pass of Kelishinin, where he erected a commemorative stone with inscriptions in Khaldian and Assyrian. Ispuinis and his son Menuas brought the empire to its peak. Under them it extended from the Zagros Mountains in the East to Palu in the North and Malatia in the West.