Zengi, Nur ad-Din's father, had seized Edessa in 1144. Deprived of their capital, the western lands of the County of Edessa continued a precarious existence for six more years. They came under increasing pressure from the Muslim states surrounding them. In 1150, the Byzantine Emperor Manuel I Komnenos expressed an interest in acquiring the rump of the County of Edessa. As their feudal overlord, Baldwin III was required to defend them in case of attack. Recognizing that the Crusaders were unlikely to hold on to these territories for much longer, Baldwin agreed to turn them over to the Byzantines.
Baldwin met with Manuel's agents at Turbessel (Tell Bashir) to negotiate the transfer of territories. Franks or Armenians who wished to remain under Latin rule were allowed to march back to the Principality of Antioch with the king, taking their possessions with them. Baldwin's small army consisted of 500 mounted knights and an unknown number of foot soldiers.