In 1138 he rebelled against his suzerain, the Seljuk sultan Ahmed Sanjar, but was defeated in Hezarasp and forced to flee.
Pada tahun 1138, Atsïz memberontak terhadap suzeranusnya, Sultan Ahmed Sanjar dari Seljuk, namun dikalahkan di Hezarasp dan terpaksa melarikan diri.