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.

Genghis Khan saw Ögedei as having a courteous and generous character.
His charisma is partially credited for his success in keeping the Empire on his father's path.
Thanks mostly to the organization left behind by Genghis Khan, and to the personality of Ögedei, the affairs of the Mongol Empire remained for the most part stable during his reign.
Ögedei was a pragmatic man, though he made some mistakes during his reign.
Ögedei had no delusions that he was his father's equal as a military commander or organizer and used the abilities of those he found most capable.

Notwithstanding reports of his charisma, Ögedei was criticized by Mongol and Persian chroniclers for a crime he committed in 1237, which according to Persian chroniclers consisted of ordering the rape of four thousand Oirat girls above the age of seven.
These girls were then confiscated for Ögedei's harem or given to caravan hostels throughout the Mongol Empire for use as prostitutes.
This move brought the Oirat and their lands under Ögedei's control following the death of Ögedei's sister Checheyigen, who previously controlled Oirat lands.
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.
Genghis Khan saw Ögedei as having a courteous and generous character. His charisma is partially credited for his success in keeping the Empire on his father's path. Thanks mostly to the organization left behind by Genghis Khan, and to the personality of Ögedei, the affairs of the Mongol Empire remained for the most part stable during his reign. Ögedei was a pragmatic man, though he made some mistakes during his reign. Ögedei had no delusions that he was his father's equal as a military commander or organizer and used the abilities of those he found most capable.
Notwithstanding reports of his charisma, Ögedei was criticized by Mongol and Persian chroniclers for a crime he committed in 1237, which according to Persian chroniclers consisted of ordering the rape of four thousand Oirat girls above the age of seven. These girls were then confiscated for Ögedei's harem or given to caravan hostels throughout the Mongol Empire for use as prostitutes. This move brought the Oirat and their lands under Ögedei's control following the death of Ögedei's sister Checheyigen, who previously controlled Oirat lands.
Ögedei Khan