He was born into a French noble family but migrated to the Holy Land, where King Baldwin I of Jerusalem made him senechal in the early 1100s and appointed him prince of Galilee in 1105/1106.
The contemporaneous Guibert of Nogent described Gervase as a "knight ... of noble blood, from the castle of Basilcas in Soissons".
[1][2] Albert of Aix referred to Gervase as "a famous and very noble man who was born in the realm of western France".
[4][5] In 1106, the Muslims of Tyre attacked the Galilean fortress of Toron while Toghtekin, the atabeg of Damascus, raided the region of Tiberias, but they could not do much harm.
[6][8][11] After Gervase's death, Baldwin granted the title Prince of Galilee to Tancred, who had held the principality before Hugh of Fauquembergues.