The Uyghurs established a Kingdom in the Turpan region with its capital in Gaochang or Kara-Khoja. The kingdom was known as the Uyghuria Idikut state or Kara-Khoja Kingdom that lasted from 856 to 1389 AD. The Uyghurs were Manichaean but later converted to Buddhism and funded the construction the cave temples in the Bezeklik Caves. The Uyghurs formed an alliance with the rulers of Dunhuang. The Uyghur state later became a vassal state of the Kara-Khitans and then as a vassal of the Mongol Empire. This Kingdom was led by the Idikuts or Saint Spiritual Rulers. The last Idikut left Turpan area in 1284 for Kumul and then Gansu to seek protection of Yuan Dynasty, but local Uyghur Buddhist rulers still held power until the invasion by the Moghul Khizr Khoja in 1389. The conversion of the local Buddhist population to Islam was completed nevertheless only in the second half of the 15th century.