His father's adopted brother and companion Borokhula rescued him. Although he was already married, in 1204 his father gave him Töregene, the wife of a defeated Merkit chief. The addition of such a wife was not uncommon in steppe culture. After Genghis was proclaimed Emperor or Khagan in 1206, myangans (thousands) of the Jalayir, Besud, Suldus, and Khongqatan clans were given to him as his appanage. Ögedei's territory occupied the Emil and Hobok rivers. According to his father's wish, Ilugei, the commander of the Jalayir, became Ögedei's tutor. Ögedei, along with his brothers, campaigned independently for the first time in November 1211 against the Jin dynasty. He was sent to ravage the land south through Hebei and then north through Shanxi in 1213. Ögedei's force drove the Jin garrison out of the Ordos, and he rode to the juncture of the Xi Xia, Jin, and Song domains. During the Mongol conquest of Khwarezmia, Ögedei and Chagatai massacred the residents of Otrar after a five-month siege in 1219–20 and joined Jochi who was outside the walls of Urganch. Because Jochi and Chagatai were quarreling over the military strategy, Ögedei was appointed by Genghis Khan to oversee the siege of Urganch. They captured the city in 1221. When the rebellion broke out in southeast Persia and Afghanistan, Ögedei also pacified Ghazni. Position as heir The Empress Yisui insisted that Genghis Khan designate an heir before the invasion of the Khwarezmid Empire in 1219. After the terrible brawl between two elder sons Jochi and Chagatai, they agreed that Ögedei was to be chosen as heir. Genghis confirmed their decision. Genghis Khan died in 1227, and Jochi had died a year or two earlier. Ögedei's younger brother Tolui held the regency until 1229. Ögedei was elected supreme khan in 1229, according to the kurultai held at Kodoe Aral on the Kherlen River after Genghis' death, although this was never really in doubt as it was Genghis' clear wish that he be succeeded by Ögedei. After ritually declining three times, Ögedei was proclaimed Khagan of the Mongols on 13 September 1229. Chagatai continued to support his younger brother's claim. World conquests Expansion in the Middle East After destroying the Khwarazmian empire, Genghis Khan was free to move against Western Xia. In 1226, however, Jalal ad-Din Mingburnu, the last of the Khwarizm monarchs, returned to Persia to revive the empire lost by his father, Muhammad ‘Ala