Tolui
Tolui was the youngest son of Genghis Khan and Börte. A prominent general during the early Mongol conquests, Tolui was a leading candidate to succeed his father after his death in 1227 and ultimately served as regent of the Mongol Empire until the accession of his brother Ögedei two years later. Tolui's wife was Sorghaghtani Beki; their sons included Möngke and Kublai, the fourth and fifth khagans of the empire, and Hulagu, the founder of the Ilkhanate. Tolui was less active than his elder brothers Jochi, Chagatai, and Ögedei during their father's rise to power, but once he reached adulthood he was considered the finest warrior of the four. He commanded armies under his father during the first invasion of Jin China (1211–1215), and his distinguished service during the Mongol invasion of the Khwarazmian Empire secured his reputation. After the fall of the cities of Transoxiana in 1220, Genghis dispatched Tolui early the following year to subjugate the region of Khorasan, which had begun to cause trouble for the Mongol armies. Tolui executed his orders with ruthless efficiency, assaulting the major cities of Merv, Nishapur, and Herat, and subjugating numerous others. Medieval chroniclers attributed more than three million deaths to the massacres he ordered at Nishapur and Merv; while these figures are considered exaggerated by modern historians, they are evidence of the abnormal brutality of Tolui's campaign. As the Mongols' traditional inheritance system was a form of ultimogeniture, Tolui was always a leading candidate to succeed his father. His position was strengthened by the elimination of Jochi and Chagatai, on account of possible illegitimacy and excessive arrogance respectively. Genghis eventually passed Tolui over in favour of Ögedei, who was known for his generosity. Tolui was on his father's last campaign when the latter died in mid-1227; as the youngest son, he became regent, in charge of his father's burial and the administration of the nation. It is possible that the two-year interregnum was lengthened by Tolui's desire to become khan himself; he nevertheless eventually swore allegiance to Ögedei, who was crowned in 1229. Tolui accompanied Ögedei after the resumption of warfare against the Jin dynasty in 1230. The campaign was successful and they returned home to Mongolia two years later. Tolui died in unclear circumstances in late 1232. The official record was that he died during a shamanic ritual while saving Ögedei from a curse; alternative theories suggest that he died from alcoholism or that Ögedei had him poisoned. Having taken over Tolui's lands and estates after his death, Sorghaghtani amassed enough wealth and supporters to ensure that her son Möngke took power in 1251, after the death of Ögedei's son Güyük.
punctuation:no_comma, startend:quotation, change_case:english_capital