The Seljuq campaigns in the Aegean refer to the ground and naval actions conducted by the Seljuk Turks, chiefly under the leadership of Tzachas of Smyrna against the Byzantine Empire. A fierce opponent, Tzachas constructed the first Turkish navy and captured a few Aegean islands, supplemented by the conquest of Smyrna and Abydos. In the aftermath of the First Crusade Alexios I launched a counter-attack which regained the territories lost. Alexios was also able to rapidly quell the threat of Abu'l Qasim, the Seljuk governor of Nicaea, who attempted to create a fleet of his own at Abydos in ca. 1090.