During the reign of Emperor Romanos II (959-963) the main enemies of Byzantium were the Hamdanid Arabs and their emir Sayf ad-Dawlah, based in Aleppo. In July 960, general Nikephoros Phocas assembled a large army -mostly from the units of Asia Minor- and invaded Crete. This altered the balance of forces in the eastern front and Sayf ad-Dawlah took the opportunity to launch large-scale raids into the Byzantine Anatolia.
Emperor Romanos II transferred Leo Phocas, Nikephoros’ brother, in the East to deal with the situation, but this did not discourage the Emir, who leading an army of 30,000 moved against the fortress of Chrisianon, in the autumn of 960. Leo Phocas being unable to confront the Arabs in open battle, preferred to organize an ambush in the rear of the Arabs, at the straits of Andrassus, in Cilicia.
The Arab troops, after the capture of Chrisianon, took the way back to their territory passing through the straits of Andrassus, where the hidden Byzantine force was waiting. On 6th November, they fell in the ambush. They were trapped in the passage and completely routed. It was an overwhelming defeat of the Arabs; the Byzantines annihilated most of the enemy forces, while the emir himself barely managed to escape.
It was a turning point in the long conflict between Byzantines and Arabs in the East. The victory enabled the Byzantines to finish the conquest of Crete and started the decline of the Hamdanids who were no longer in position to raid in Anatolia.