Jalal ad-Din Mingburnu
The execution of 450 envoys and tradesmen of Genghis Khan by Khwarezm Shah 1218 was an announcement of war. The Mongol troops invaded Khwarezm Empire in 1219. Although Khwarezm Shah possessed an army outnumbering the Mongol troops dozen of times, he lacked the courage and initiatives to unite his forces and fight back. The Mongol troops sacked cities Otrar, Buhara, Merv and Samarkand. Shah's warlord Temur-Melik led a daring resistance when the Mongol troops besieged city of Khujand. Shah's son Jalal ad-Din Mingburnu courageously battled with the Mongol army in 1221, but was defeated and escaped to the river Indus.