Noun
atabeg (plural atabegs)
(historical) A high medieval Turkish feudal title, originally charged with the caretaking and mentoring of the realm's crown prince.
Adhemar is said to have carried the Holy Lance in the Crusaders’ desperate breakout at Antioch on 28 June 1098, in which superior Islamic forces under the atabeg Kerbogha were routed, securing the city for the Crusaders. Source: Internet
Mahmud's death was followed by a civil war between his son Dawud, his nephew Mas'ud and the atabeg Toghrul II. Source: Internet