Tûl Isra was the administrative capital of Sîrayn. It was located on the east bank of the Hayk Sarzain, a ravine filled by the Maudar River to form a deep lake, in the midst of the province of Isra. For centuries, the Tarb of this city had ruled six of the seven cities in the Mezin-tarb.When the schemes of Tartas Izain, the Taraskon in the years following T.A. 1632, succeeded, the conquest of Tûl Harar completed Tûl Isra's dominion over the lands of Greater Harad.