The Battle of the Amu Darya was a decisive battle fought between the armies of the Mongol Empire and the Khwarezmian Empire in Turkmenistan in 1221 during the Mongol conquest of Khwarezmia. The vast Khwarazmian host, led by Shah Muhammad II of Khwarazm, was annihilated by a smaller Mongol army a third of its size at a crossing of the Amu Darya river in Central Asia, and the Mongols slew the Khwarazmshah and most of his soldiers. The Khwarazmian defeat at the Amu Darya prevented the Khwarazmians from destroying Jebe's horde, and enabled the Mongols to penetrate deeper into the Khorasan region and destroy Khwarezm's power.
Background[]
In 1218, the Mongol Empire went to war with the Central Asian Khwarazmian Empire after Shah Muhammad II of Khwarazm executed several Mongol envoys (whom he believed were spies). Genghis Khan sent his son Tolui Khan with his generals Jebe and Khubilai to invade Khwarezm and retaliate against this great offense. In three hordes, the Mongols pushed into Central Asia, first capturing and destroying the cities of Samarkand, Bukhara, and Urgench and massacring their populations. While Tolui and Khubilai then marched south from Urgench to attack Gorgan, Jebe's horde attacked the Khwarazmian city of Merv farther south, repeating the Mongol tactic of capturing and desolating the city and the surrounding countryside. Jebe's army then encamped to the east of the city to rest following its razing of Merv, which gave the Khwarazmshah the opportunity to move his and Tughluq's armies from Persia to confront and destroy the Mongol horde. The two Khwarazmian armies attacked the Mongol army at present-day Zahmet on the Amu Darya river, initiating one of the greatest battles of the campaign.
Battle[]
Start of the battle[]
The Mongol army positioned itself on the east bank of the river, guarding a key river crossing with their cavalry archers and two catapult units; they also concealed several lancers in a treeline behind their right-angle defensive formation. As Tughluq's army was the first Khwarazmian force to appear on the battlefield, it halted at the river crossing, awaiting Shah Muhammad's reinforcements. The Chinese catapult crews took advantage of this by launching flaming projectiles at the Khwarazmian soldiers on the other bank, inflicting heavy losses and even convincing a few of their units to retreat from the battlefield. This drawn-out series of missile attacks ended when the catapults ran out of ammunition, by which time Muhammad's army had joined forces with Tughluq.
Khwarazmian assaults[]
The first Khwarazmian assault
Rather than exploit the presence of two crossings further up and down the river, the overconfident Khwarazmians decided to attack the Mongol force head-on across the river crossing, taking advantage of the depleted ranks of many of the Mongol cavalry units, which had yet to replenish their manpower from the taking of Merv. The Mongol horse archers, in their right-angle formation, were distant enough from the crossing to shower the advancing Khwarazmian infantry and cavalry with arrow fire, inflicting heavy losses. The Khwarazmians sent regiment after regiment into the kill-zone, and, when the Khwarazmian cavalry and spearmen managed to make contact with the Mongol horse archers, the Mongol lancers emerged from the trees to repel them. The Mongols suffered equally heavy losses, but Tolui rallied his faltering units at each turn, and he personally charged into battle on occasion, helping the lancers to attack the Khwarazmian assault units from behind. Around five Khwarazmian assaults were repulsed, and several units were utterly annihilated by arrow fire.
Mongol counterattack[]
The Khwarazmians retreating across the river
Soon, the bulk of the Khwarazmian assault units were streaming across the river in retreat, leaving their dead comrades on the far bank or in the water. The Mongols proceeded to launch a counterattack, catching the slowed-down Khwarazmians at the crossing and butchering them. They then killed the Khwarazmian archers who were guarding the crossing and harrying the Mongol cavalry, and they went on to overwhelm Shah Muhammad and his bodyguards, killing them; Tughluq, the other Khwarazmian commander, had already been killed during the main assault.
Dead Khwarazmians in the Amu Darya river
The leaderless Khwarazmians then routed from the field, with the Mongol cavalry ruthlessly pursuing their remnants and capturing 193 of them. The Khwarezmians lost 2,083 men, or 88% of their total strength; meanwhile, the Mongols lost over half of their small army. However, the remnants of the Khwarazmian armies now numbered less than half of the surviving Mongol force, rendering a second battle impossible. An army which had taken to the field with three times the strength of the Mongol horde was now half the size of half of the Mongol's original strength.
Aftermath[]
The Mongol and Khwarazmian casualties on the riverbank
The remnants of the Khwarazmian armies retreated further west, streaming past the burned-out city of Merv and towards Persia, where they were presumably sent to garrison local cities and rebuild their strength. The humiliating defeat led to the Khwarazmians suing for peace and offering a large sum of money, but Tolui's counter-offer of making Khwarezmia a vassal state was soundly rejected (as expected), and the Mongols proceeded to invade deeper into Khwarezmia and continue on their path of destruction.