Following the Mongol invasion of Khwarezm Jalal ad-Din was forced to flee towards the Hindukush, where he began to muster additional troops to face the Mongols. With the arrival of over 30,000 Afghan warriors from what is now Afghanistan; his strength reportedly rose to 60,000. Though badly equipped and ill-managed being tribal Lashkar, they managed to defeat the Mongol hordes under the command of Shikhikhutug after the day long battle at Parwan in the vicinity of Ghazni. After the battle the Great Khan personally headed southwards with an army of 50,000 and crushed Jalal ad-din's army at the Battle of Indus thus completing the conquest of Afghanistan. But the Khwarezmian prince did not prove himself as able in victory as he had been in defeat. In a row over the booty; a Mongolian white horse; between his father-in-law and an Afghan Chief, he sided with his father-in-law. The Afghans left their camp fire burning and left the same night, despite being completely exhausted by the day's fighting. Finding himself without more than half of his fighting strength Jalal ad-Din retreated the next day towards the east. As he no longer had sufficient resources to last another battle, they headed towards the Indus river to the area north of the present city of Kalabagn. The Mongols caught up with him on the banks of the Indus and defeated him what in now referred to as the Battle of Indus.