Irghiz River skirmish

The Irghiz River skirmish was a minor engagement fought between forces of the Khwarazmian Empire and the Mongol Empire during the early 13th century. While the occurrence of the skirmish itself is well-attested, its precise dating is uncertain, since the major chroniclers of the period give differing accounts. Modern historians have proposed two possible dates: 1209 or 1219. The background events are similar for each possible date: Genghis Khan, khagan of the Mongols, sent an army under his general Subutai to attack hostile forces (either a Merkit confederation or the renegade Naiman prince Kuchlug) in the former lands of the Qara-Khitai dynasty. Shah Muhammad, the ruler of the Khwarazmian Empire, received news of large armies operating along his northern borders and set out to confront them.

The Mongol army, which possibly also included the general Jebe and Genghis' eldest son Jochi, was surprised by the Shah very soon after defeating their initial target; Muhammad rejected peace overtures and initiated battle. The fierce engagement, between two armies of approximately equal strength, lasted until nightfall, but the Mongols probably had the upper hand. However, since they had been instructed to avoid any possible fighting, they abandoned their camp in secret during the night. The prowess of the Mongol soldiers displayed during the skirmish has been cited as a major reason for the Shah choosing a defensive strategy during the open warfare of 1220–21, for which this was a preliminary encounter.