Abbasid invasion of 782

The Abbasid invasion of Asia Minor in 782 was one of the largest operations launched by the Abbasid Caliphate against the Byzantine Empire. The invasion was launched as a display of Abbasid military might in the aftermath of a series of Byzantine successes. Commanded by the Abbasid heir-apparent, the future Harun al-Rashid, the Abbasid army reached as far as Chrysopolis, across the Bosporus from the Byzantine capital, Constantinople, while secondary forces raided western Asia Minor and defeated the Byzantine forces there. As Harun did not intend to assault Constantinople and lacked ships to do so, he turned back.

• http://en.wikipedia.org/wiki/Abbasid invasion of 782