Kaysun

Kaysun stood in the hill country north of the Euphrates, where the fortress of the same name guarded a settlement known in Armenian as Kesun. In the early twelfth century it was part of the principality of the Armenian ruler Kogh Vasil and a home of the chronicler Matthew of Edessa. Its position exposed it to the struggles of Armenians, Crusaders and Muslim rulers: the Seljuks took it in 1150, and Nur al-Din seized it nine years later.