Wikipedia
Oyiradai (died 1425) was the Mongol Khan of the Northern Yuan dynasty based in Mongolia. Oyiradai ascended to the throne of Khagan in 1415 with the help of the Oirats after Delbeg Khan was killed by eastern Mongols led by Adai Khan or perished in a battle with the Ming Dynasty in the same year. His ascent to the throne was meant to legitimize the Oirats’ rule because he was a direct descendant of Ariq Böke. Oyiradai’s reign only covers western Mongolia but this was expanded near his death: during his rule, with help from Ming China, western Mongols headed by Toghan launched two significant campaigns in 1422 and 1423 against Arughtai chingsang and Adai Khan respectively, controlling eastern and central Mongol territory, and both resulted in victory for Oirats.
After Oyiradai Khan’s death in 1425, the conflicts among Oirats and western Mongol clans left the throne of khan vacant for several years, and it was not until 1433 when the Oirats finally crowned Tayisung Khan (Toghtoa Bukha) as the new khan. Meanwhile, in the east, the Oirats’s rival eastern Mongol clans proclaimed Adai Khan as the Great Khan in 1425, which eventually resulted in half a decade of the simultaneous existence of two khans supported by opposing Mongol clans.