Jochi Khan (Mongolian: , ; ; ; ; also spelled Juchi; Djochi, and Jöchi c. 1182– February 1227) was a Mongol army commander who was the eldest son of Temüjin (aka Genghis Khan), and presumably one of the four sons by his principal wife Börte, though issues concerning his paternity followed him throughout his life. An accomplished military leader, he participated in his father's conquest of Central Asia, along with his brothers and uncles. Early life There is some question as to Jochi's true paternity. Shortly after Börte's marriage to Temüjin (later to become Genghis Khan), she was abducted by members of the Mergid confederation. She was given to a certain Chilger Bökh, who was the brother of the Yehe Chiledu, as a spoil of war. She remained in Chilger Bökh's captivity for a few months before she was recovered by Temüjin. Shortly afterwards she gave birth to Jochi. By all accounts, Temüjin treated Jochi as his first son, but a doubt always remained whether Temüjin or Chilger Bökh was his real father. Jochi's descendants, although they formed the oldest branch of Temüjin's family, were never considered for the succession in claiming their father's heritage and there were signs of estrangement between Jochi and Temüjin. Wars of conquest In 1207, Jochi conquered several of the forest peoples in Siberia, extending the northern border of the Mongol Empire for the first time. On behalf of his father, Jochi led two campaigns against the Kyrgyz, in 1210 and in 1218. Jochi played a major role in the Khwarezm war of 1219–1221 in Central Asia – his forces captured the towns of Signak, Jand, and Yanikant in April, 1220, during this war. Subsequently, he was given the command of operation against the city of Urgench (Gurganj, in present-day Turkmenistan), the capital of the Khwarezmian Empire. Here the siege of the town suffered delays because Jochi engaged in extensive negotiation with the town to persuade it to surrender peacefully and to save it from destruction. Jochi's brother Chagatai regarded this action as militarily unsound: Chagatai wanted to destroy the city but Temüjin (now Genghis Khan) had promised the city to Jochi after his victory. This difference of opinion on military affairs deepened a rift between Jochi and Chagatai. Genghis Khan intervened in the campaign and appointed Ögedei as the commander of the operation. Ögedei resumed the operations vigorously – capturing, sacking and thoroughly destroying