Historians are divided on the historicity of Jabala due the lack of contemporary source material, with some arguing his personality was essentially a literary device of later Islamic writers.
However, a seal dated to the late 6th or early 7th century inscribed with the words 'Gabala, patrikios' next to etches of Christian crosses has led to speculative identification with Jabala ibn al-Ayham by the historian Irfan Shahid.
[1] In the stories of Jabala in the Islamic literature, he is figured as the last Ghassanid king and a military leader of the Byzantine Empire's Christian Arab contingent during the Muslim conquest of Syria.
There are different versions of the stories, but they generally have Jabala arrive to the Muslim capital at Medina with his entourage, set off for the Hajj pilgrimage with Caliph Umar, have an altercation with a lowly pilgrim whose nose he ultimately breaks, threaten to leave Islam, and finally make a nightly escape which ends with his relocation to Byzantine territory.
[1] Jabala's flight to Byzantium supposedly occurred in c. 639 and he made the trek through Raqqa (Byzantine Callinicum) with 30,000 of his or allied Christian Arab tribesmen (incl.