Titular count of Edessa (from 1159) and seneschal of the kingdom of Jerusalem (1176-1193).
Joscelin was born around 1134, the son of Joscelin II of Courtenay, count of Edessa, and Beatrix of Saône. The capture of his father by Nûr al-Din in 1150 left Joscelin and his mother as effective rulers of a county of Edessa that Turk ish pressure had reduced to a rump west of the Euphrates. The Turkish invasion that followed this event overran the rest of the county except for the chief stronghold of Turbessel (mod. Tellbaflar Kalesi, Turkey) and a few other fortresses, which Joscelin and Beatrix sold to the Byzantine emperor Manuel Komnenos later the same year.
The Courtenay family took refuge in the kingdom of Jerusalem, where Joscelin’s sister Agnes married Amalric, younger brother of King Baldwin III, in 1157. Joscelin himself seems to have been recognized as titular count of Edessa on the death of his father in 1159 (he was usually styled “Count Joscelin” by the Jerusalem chancery). The grant to him by Baldwin III of the newly captured town of Harenc (mod. Harim, Syria) between 1160 and 1163 might be regarded as an attempt to reestablish a territory for him in northern Syria. However, the defeat of the Franks by Nûr al- Dīn at Artah (1164) led to the loss of Harenc and the imprisonment of Joscelin until 1176.
Joscelin’s release was procured by his sister, whose son Baldwin IV was now king of Jerusalem. On his return Joscelin was appointed seneschal of the kingdom, and through his marriage to Agnes, daughter of Henry of Milly, and various royal grants he built up a conglomeration of lands and rights in the territory northeast of Acre (mod. ‘Akko, Israel) around Château du Roi, which came to be known collectively as the Seigneurie de Joscelin (“Lordship of Joscelin”).
In the factional politics that intensified during the reign of Baldwin IV (1174-1185), Joscelin was a firm ally of the king’s sister Sibyl and her second husband Guy of Lusignan. On the death of the short-lived young king Baldwin V (1186), he was instrumental in securing the joint accession of Guy and Sibyl to the throne, in defiance of Count Raymond III of Tripoli and the Ibelin family. Joscelin was rewarded with new grants of lands and money fiefs, including the lordships of Toron and Châteauneuf, while his two daughters were betrothed to members of Guy’s family.
Almost all of the seneschal’s lands were overrun by Sal- adin’s forces after the battle of Hattin (1187), and the obscurity of his subsequent career is such that the date of his death cannot be determined with certainty. By 1200 the Seigneurie de Joscelin had passed to his elder daughter, Beatrix, and her husband Otto of Botenlauben, who later sold it to the Teutonic Order (1220); the records transferred with this sale represent the only surviving baronial archive of the kingdom of Jerusalem.