Sayf al-Dawla
In the middle of the 10th century, after a period of expansion on its eastern frontier, led by John Kourkouas, at the expense of the Muslim border emirates, the Byzantine Empire was confronted by the Hamdanid prince Sayf al-Dawla. In 945, Sayf al-Dawla made Aleppo his capital, and soon established his authority across northern Syria, much of the Jazira (Upper Mesopotamia), and what remained of the Abbasid Caliphate's frontier districts ("thughūr") with Byzantium. Committed to the spirit of "jihad", during the following two decades the Hamdanid ruler emerged as the main enemy of the Byzantines. By the time of his death in 967, Sayf al-Dawla was said to have fought against the Byzantines in over forty battles.