 His name is written in "The Secret History of the Mongols" as Qurčaqus.According to Volker Rybatzki and Christoph Baumer its original form could be Cyriacus, a Syriac name.While per Lev Gumilev, original form may be Gregorius as well.He succeeded Kerait ruler Sariq Khan (according to Timothy May, he was his father, while Isenbike Togan says Sariq was just pre-Christian name of Marcus Buyruk Khan) in 1150.