Genghis Khan defeats the renegade Khwarazmian prince Jalal al-Din at the Battle of the Indus, completing the Mongol conquest of Central Asia.

Genghis Khan, also known as Chinggis Khan, was the founder and first khan of the Mongol Empire. After spending most of his life uniting the Mongol tribes, he launched a series of military campaigns, conquering large parts of China and Central Asia.

The Khwarazmian Empire, or simply Khwarazm, was a culturally Persianate, Sunni Muslim empire of Turkic mamluk origin. Khwarazmians ruled large parts of present-day Central Asia, Afghanistan, and Iran from 1077 to 1231; first as vassals of the Seljuk Empire and the Qara Khitai, and from circa 1190 as independent rulers up until the Mongol conquest in 1219–1221.

Jalal al-Din Mangburni, also known as Jalal al-Din Khwarazmshah, was the last Khwarazmshah of the Anushtegin dynasty. The eldest son and successor of Ala ad-Din Muhammad II of the Khwarazmian Empire, Jalal al-Din was brought up at Gurganj, the wealthy capital of the Khwarazmid homeland. An able general, he served as second-in-command to his father in at least one battle; however, since he was the son of a concubine, he was challenged as successor by a younger brother, whose cause was supported by the powerful Queen Mother, Terken Khatun. Nevertheless, after the Mongol conquest of the Khwarazmian Empire led to his father's flight and death on an island in the Caspian Sea, Jalal-al Din gained the loyalty of the majority of Khwarazmian loyalists.

The Battle of the Indus was fought on the banks of the Indus River, on 24 November 1221, between the armies commanded by Jalal al-Din of the Khwarazmian Empire, and Genghis Khan of the Mongol Empire. The battle, which resulted in an overwhelming Mongol victory, was the concluding engagement in the Mongol invasion of the Khwarazmian Empire.