Sibylla was the eldest daughter of King Amalric and the only daughter of Agnes of Courtenay. Her father died in 1174, making her heir presumptive to her younger brother, King Baldwin IV. When it became clear that 13-year-old Baldwin had contracted leprosy, the matter of Sibylla's marriage became urgent. The regent, Count Raymond III of Tripoli, arranged for her to marry William Longsword of Montferrat in late 1176, but within a year William died, leaving her pregnant and in possession of the Cou