Originally in Byzantine service, he rebelled and seized Smyrna, much of the Aegean coastlands of Asia Minor and the islands lying off shore in 1088–91.

He is also mentioned in the 13th-century Danishmendname as 'Chavuldur Chaka' (Turkish: Çavuldur Çaka),[1] but it is not a very reliable source due to the semi-legendary nature of its material.

Tzachas entered Byzantine service and advanced rapidly through imperial favour, receiving the title of protonobelissimos and rich gifts.

Employing Christian craftsmen, he built a fleet, with which he captured Phocaea and the eastern Aegean islands of Lesbos (except for the fortress of Methymna), Samos, Chios and Rhodes.

[3][4] Some modern scholars have speculated that his activities during this time may have been in conjunction, and perhaps even coordination, with two contemporary Byzantine rebels, Rhapsomates in Cyprus, and Karykes in Crete.