The young Joscelin was taken prisoner at the Battle of Azaz in 1125, but was ransomed by Baldwin II, king of Jerusalem. In 1131, his father Joscelin I was injured in battle with the Danishmends, and Edessa passed to Joscelin II. Joscelin II refused to march the small Edessan army out to meet the Danishmends, so Joscelin I, in his last act, forced the Danishmends to retreat, dying soon after.
Joscelin II ruled the weakest and most isolated of the Crusader states. In 1138 he allied with Antioch and Byzantine emperor John II Comnenus to attack Zengi, atabeg of Aleppo, although Zengi defeated them. Back in Antioch, sentiment agains the Byzantine Empire, which John was trying to extend into the northern Crusader states, led to a riot, engineered by Joscelin. John was forced to return home.
In 1143 both John II and Fulk of Jerusalem died, leaving Joscelin with no powerful allies to help defend Edessa. In 1144 Zengi invaded and captured Edessa itself. Joscelin fled to Turbessel, where he held the remnants of the county west of the Euphrates. When Zengi died in 1146, Joscelin attempted to recapture Edessa but was defeated by Zengi's son Nur ad-Din. The Second Crusade, called in response to the fall of Edessa, was also unable to defeat the Muslims. Joscelin was taken prisoner in 1150 and died in 1159.
|County of Edessa||
Joscelin III (nominal count)