During the reign of Sultan Sanjar or Sinjar of the same house, in the middle of the 11th century, Mer y was overrun by the Turkish tribes of the Ghuzz from beyond the Oxus.
In 1221 Mer y opened its gates to Tule, son of Jenghiz Khan, chief of the Mongols, on which occasion most of the inhabitants are said to have been butchered.
On the death of the grandson of Jenghiz Khan Mer y was included (1380) in the possessions of Timur-iLeng (Tamerlane), Mongol prince of Samarkand.
Mer y remained in the hands of Persia until 1787, when it was captured by the emir of Bokhara.
East of the old Seljuk capital is Giaur Kalah, the Mer y of the Nestorian era and the capital of the Arab princes.