During his rule, Adai was able to consolidate and expand his power, eventually unifying both the central and eastern Mongol territories in 1425. However, his conquest of western Mongol territory was checked by the
Oirats and both sides continued the war for unification for decades. Riding on the success of unifying central and eastern Mongol territories, Adai proclaimed himself as Khagan with support of central and eastern Mongol clans in 1425, the same year his rival khan in the west,
Oyiradai, was killed. Adai and Arughtai crushed the Oirats and killed several of their leaders. After capturing the Oirat nobles, Adai married Ugetchi Khashikha's wife, Öljeitü the Beauty, who had been a consort of
Elbeg Khan (r.1392–1399), and enslaved Bahamu's son (the future Toghan taishi). Although Adai Khan’s authority did not fully reach western Mongols who did not recognize him as supreme ruler, the western Mongol clans did not have a khan of their own so Adai Khan remained as the sole Mongol ruler for the next eight years, at least in name. Elbeg's daughter and the Oirat taishi Bahamu's widow, Samar, persuaded the Khan to release her son, now named Toghan, to western Mongolia. However, in 1433, Toghan raised a rebellion and western Mongols finally crowned
Toghtoa Bukha (or Toγtoγa Buqa) with the title of Tayisung Khan as their next khan, which resulted in half a decade of the simultaneous existence of two khans supported by opposing Mongol clans.
Decline After two decisive campaigns in 1422 and 1423, Adai Khan lost all of the territory gained in the past and in 1430, the third Oirat victory wiped out his major strength, after which he could no longer mount any effective offensives and was forced on the defensive. Both sides attempted to utilize the stalemate to prepare for the next stage but Adai Khan could not recover from the previous loss. The Oirats soon launched another round of offensives and in the fourth decisive Oirat victory in 1434, Adai Khan’s major advisors, Arughtai, and others, were killed. Adai Khan’s downfall was certain.
Death In 1438, Adai Khan was defeated in
Ejin when his territory was overrun by the Oirats and their allies. Adai sought refuge in the
Eight White Tents of
Genghis Khan, however, being unarmed, he was murdered by Togoon
taishi of the Oirat. ==See also==