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.
During their reigns great works were constructed around Van, including the aqueduct of Shamiram‑Su, •45 miles in length, completed by Menuas, which brought the pure water of the Khoshab River to the eastern shores of Lake Van (whose water is undrinkable), enabling the King to found there a "Menuas city." This canal irrigates the plain of Van even to the present time.