What is "turbessel"

Turbessel (, , or ) is a fortress and bronze-age tumulus in south-eastern Turkey, near the village of Gündoğan in the district of Oğuzeli, within Gaziantep Province.

While the site had been occupied since the bronze age, the fort gained importance during the Byzantine Empire and came under control of local Armenian lords in the late 11th century. Following the First Crusade, as a part of the County of Edessa it was one of the main strongholds of Frankish counts such as Joscelin. After the fall of Edessa to Zengi, it became the principal city of what remained of the County until it was eventually sold to the Emperor Manuel I Comnenus in 1150. It fell to Nur ed-Din's Muslims within the year.