In 615 Hijri (1266-67 AD) Genghis Khan conducted an expedition to the Islamic countries. He approached Anjar and deployed his three sons Bhurji Khan, Uktai Khan and Chugtai Khan to besiege Anjar. Then Alak sent Nuiya and Manankri Buka with one army towards Khozand and Nabakat and he himself set off towards Bukhara with his youngest son Tulikhan. On learning of this Mongol attack, Khawarizm Shah sent a large army of sixty thousand soldiers towards Anjar and an army of thirty thousand cavalry towards Bukhara. Then, deploying an army of two hundred and ten thousand soldiers for the defense of Samarkand and sixty thousand men for the repair of the bastions and forts, he himself left for Khurasan from Samarkand.
Khawarizm Shah reached Balkh from Samarkand and sent his family and wealth to Majendan. On reaching Balkh, he consulted with his emirs and captains about the strategy to be adopted against the Mongols. Khawarism Shah had seven sons. Meanwhile, the son named Jalaluddin saw his father in a state of fear and said: If you want to go to Iraq, you can leave the command of the army in my hands and go safely. If Allah wills, I shall attack the enemy and pitch my tent beyond the river Jain. Give me Mauroun Na and you handle only Iraq and Khurasan.