The Qays–Yaman rivalry for power and influence in Syria dated to the early Umayyad period in the 680s and remained potent during Abbasid rule, which began in 750.
The pro-Umayyad faction raised support from Yamani and Qaysi tribesmen and affiliates, but feared that the ardently pro-Abbasid Ibn Bayhas would not come to their side.
They resolved to neutralize him by convincing the Abbasid governor that Ibn Bayhas was a leader of the Zawaqil, desert brigands who were devastating the Syrian countryside during the civil war.
[3] Soon after Ibn Bayhas was imprisoned, the pro-Umayyad rebellion was launched, with a descendant of the Umayyad caliph Mu'awiya I (r. 661–680), Abu al-Umaytir, at the helm.
[5] Large parts of Syria, namely Damascus, the Beqaa Valley, most of the coastal cities, such as Sidon, and Jund Hims (district of Homs), came under Abu al-Umaytir's authority.
Ibn Bayhas remained encamped in the Ghouta gardens, which surround Damascus, attacking anyone leaving or entering the city.
[8] Abu al-Umaytir called on his Yamani supporters from the Beqaa, Baalbek and Sidon to relieve the siege, whereupon tens of thousands of his loyalists arrived and engaged in a heavy battle with the Qaysi besiegers.
The Banu Numayr gave Maslama their oath of allegiance and together they assaulted Damascus, arresting Abu al-Umaytir in his residence, the Green Palace.
Maslama gained oaths of allegiance as caliph from the Umayyad family members and mawali in the city, while he rewarded the Qays with plots and pasturelands.
[10] With help from the Qaysi defectors inside Damascus, Ibn Bayhas's men scaled the Bab Kaysan gate and entered the city victoriously on 13 September 813.
[12] Although he governed with the recognition of the Abbasids, Ibn Bayhas ruled "purely on his own" and worked to strengthen the Qaysi position in the district at the expense of the hitherto dominant Yaman, according to the historian Paul Cobb.
The conflict was centered around the Yamani-dominated villages of Mezzeh, Darayya and Beit Lihya in the Ghouta where Abu al-Umaytir and Maslama were being protected.
[12] Shortly afterward, Ibn Bayhas had to contend with another Umayyad revolt, this time led by a descendant of Caliph Uthman (r. 644–656), Sa'id ibn Khalid al-Faddayni, who gathered around him tribesmen of the Yamani Bali and Qaysi Fazara tribes, as well as Umayyad kinsmen and remnants of the pro-Umayyad rebels from the Ghouta and Damascus in the Balqa (central Transjordan).