The clash near al-Jabiya (15 AH / 636)

The Encyclopaedia of Islam says that the battle of the Yarmuk was also known as the battle of "Djabiya", and that it lasted more than a month if the preliminary manoeuvring is counted. It began near al-Jabiya, the traditional base of the Ghassanids, and ended on 12 Rajab 15/20 August 636. ¹ This record covers only the opening phase, the clash near al-Jabiya; the main battle is described in the battle of the Yarmuk and the wider campaign in the conquest of Syria.

The article says the Byzantine forces came from Homs under the general Vahan, probably the Master of Soldiers for the East, together with Theodore Trithurios, the treasurer. ¹ Jabala ibn al-Ayham, king of the Ghassan, led the Ghassanid forces, and other Christian Arabs recruited by Heraclius in upper Mesopotamia and elsewhere took part. ¹ The Muslim forces under Abu Ubayda ibn al-Jarrah had withdrawn from Homs and Damascus before the stronger Byzantine armies advancing from the north. They fell back to a line between Dayr Ayyub and Adhri'at, where they waited for more than a month in a strong position to deter any Byzantine move further south. ¹

On 13 Jumada II 15/23 July 636 the Muslims won an initial clash near al-Jabiya. ¹ The article on al-Jabiya likewise says that a skirmish with the Byzantines took place there and that, after the victory, the booty was collected there. ² The Encyclopaedia of Islam gives no further detail of this clash: no commander other than the general command of Abu Ubayda, no numbers and no casualties.

The article adds that the Byzantines tried to use the waiting period to familiarise their forces with the Muslims and, without success, to encourage desertion and dissension among them, and that both sides received reinforcements. ¹ The decisive fighting followed at the Yarmuk, between the Wadi al-Rukkad and the Wadi al-Allan (see Wadi al-Rukkad). ¹

The article stresses that no documentary records or eyewitness accounts of the whole battle survive, that the account preserved by Ibn Asakir in his history of Damascus is probably the best, and that all figures for the numbers of combatants and the casualties should be treated with suspicion. ¹ The existing museum record of the battle of the Yarmuk also notes that al-Tabari reports differing years, 15 AH from al-Waqidi and 13 AH from Sayf, so the year of the whole campaign is debated in the Arabic sources even though the Encyclopaedia of Islam gives 636.