Sartaq (or Sartak, Sartach, Mongolian: Сартаг, Tatar: Сартак) Khan (died 1257) was the son of Batu Khan and his senior wife Boraqchin of Alchi Tatar.
[3] Boraqchin acted as regent Dowager before Sartaq eventually succeeded Batu as khan of the Golden Horde.
Alexander received yarlyk (license) to become Grand Duke of Vladimir in vassalage to the Mongol Khanate.
He died in 1256 before returning from Great Khan Möngke's court in Mongolia, less than one year after his father, probably having been poisoned by his uncles Berke and Berkhchir.
Their daughter Maria Glebovna Belozerskaya married Daniel Alexandrovich (the son of Alexander Nevsky), and was the mother of Ivan Kalita.