On 24 November 1221, the Battle of the Indus was fought between the Mongols under Genghis Khan against the Khwarazm under Jal al-Din during the Mongol Invasions.
Why did it happen?
In 1206, after years of tribal warfare, Temujin united the Mongol tribes and declared himself Genghis Khan, or “Very Mighty King.” In 1219, Genghis Khan turned his attention towards the Khwarazm Empire in Central Asia, which controlled the Silk Road connecting Europe and the Middle East with East Asia. After the Siege of Samarkand in 1220, Shah Muhammad II appointed his son Jal al-Din as his successor before exiling himself to an island in the Caspian Sea. Jal al-Din retreated into the Punjab, where he defeated the Mongols at the Battle of Parwan in October 1221. However, when Genghis Khan arrived to command the Mongols in person, Jal al-Din sought help from the Delhi Sultanate and led his army to the Indus River. On 24 November, the Mongols caught up with Jal al-Din’s army as they prepared to cross the Indus River.
Who was involved?
The Mongol army at the Indus numbered 50,000 cavalry. Mongol armies under Genghis Khan were divided into groups of 10 (arbans), 100 (zunns), 1,000 (myangans) and 10,000 (tumens). The Mongol forces normally consisted of a combination of light horse archers and heavy lancers, with discipline being valued over rigid regimentation. As stated by Saul David, “Genghis Khan himself developed particular mounted maneuvers [sic] for these men, drilling them tirelessly until they became second nature” (David, 2009, p.82). The Khwarazm army at the Indus numbered 30,000 cavalry.
What happened?
Deciding not to wait for the Mongols to make the first move, Jal al-Din attacked the Mongol left wing with his right wing, which pushed the surprised Mongols back. At the same time, cavalry from the Khwarazm left wing reinforced the centre, which then assaulted the Mongol centre. Genghis Khan then ordered 10,000 light cavalry to scale the mountain ridge to the right of his army. Just as the Khwarazm cavalry began gaining the advantage in the battle, the Mongol light cavalry descended from the ridgeline to attack the exposed flank of the Khwarazm left wing and centre. After taking command of the Mongol left wing, Genghis Khan then led a counterattack against the Khwarazm right wing where, facing encirclement, Jal al-Din escaped with 11,000 horsemen across the Indus River. The rest of the Khwarazm army was either killed or drowned as they attempted to cross the river. The Mongols lost 9,000 horsemen during the battle.
What changed as a result?
The Battle of the Indus was a Mongol victory. In the aftermath of the battle, Jal al-Din sought refuge in the Delhi Sultanate, only to be rebuffed by Sultan Iltutmish, who was unwilling to risk war with the Mongols. Subsequently, Jal al-Din spent the next ten years fighting a border war with the Mongol Empire before being murdered in 1231. Genghis Khan himself passed away in 1227, but the Mongol Empire continued to expand under his successors until it controlled 22% of the Earth’s landmass. However, after the death of Mongke Khan in 1259, the Mongol Empire split into four successor states: The Golden Horde, Ilkhanate, Chagatai Khanate, and the Yuan Dynasty under Kublai Khan. The Chagatai Khanate invaded India numerous times between 1297 and 1327 before Sultan Muhammad bin Tughlug bribed the Ilkhanate to stop the attacks. After that, India employed Mongol horsemen as mercenaries before the Delhi Sultanate was sacked by the armies of Timur in 1398.
Bibliography
David, Saul. War: The Definitive Visual History. New York, Dorling Kindersley, 2009.
Kings and Generals. “Mongols: Fall of Khwarezm - Battles of Parwan and Indus DOCUMENTARY.” YouTube video, 13:08. February 12, 2018. www.youtube.com/watch?v=WjS1FbHLIxM
Lanning, Michael Lee. The Battle 100: The Stories Behind History’s Most Influential Battles. Naperville, Sourcebooks, 2003.
Rickard, John. “Battle of the Indus, 24 November 1221.” History of War. Last revised April 7, 2010. www.historyofwar.org/articles/battles_indus_1221.html