The Abbasid revolution in Damascus in 750 ended the Ummayad caliphate and transferred the capital to Baghdad. The Abbasids distrusted the Armenian nakharars, particularly the two leading houses—the Bagratunis and the Mamikonians—for their pro-Ummayad and pro-Byzantine sentiments, respectively. Most of the Armenian public and leaders in turn held a deep hatred toward the Abbasids. The political situation rapidly degenerated into chaos, rebellion, and bloodshed. From 747 to 750 and again in 774-775, led by several nobles, particularly the pro-Byzantium Artavazd and Mushegh Mamikonian, Armenian rebellions in different regions attempted to overthrow Arab rule. 1
L'importante fiscalité que les Abbassides font subir à l'Arménie, génère ensuite le mécontentement, et une première révolte éclate en 771 sous la conduite d'Artavazd Mamikonian, mais celle-ci, faute du soutien des autres nobles, est écrasée et Artavazd doit se réfugier à Byzance. Les impôts sont ensuite doublés par les Arabes et une autre révolte éclate peu après, conduite par Moušel Mamikonian, qui réussit à obtenir le soutien des autres familles nobles, y compris celle des Bagratouni. L'armée arménienne livre bataille aux forces arabes à Bagrévand , mais elle est vaincue et la plupart des nobles arméniens y sont tués. 2
(The important taxation that the Abbasids imposed on Armenia generated discontent, and a first revolt broke out in 771 under the leadership of Artavazd Mamikonian, but this one, for lack of the support of the other nobles, was crushed and Artavazd had to take refuge in Byzantium. The taxes were then doubled by the Arabs and another revolt broke out soon after, led by Moušel Mamikonian, who succeeded in obtaining the support of other noble families, including that of the Bagratouni. The Armenian army battles the Arab forces in Bagrévand , but it ws defeated and most of the Armenian nobles were killed there.)
The Battle of Bagrevand was fought on 25 April 775, in the plains of Bagrevand, between the forces of the Armenian princes who had rebelled against the Abbasid Caliphate and the caliphal army. The battle resulted in a crushing Abbasid victory, with the death of the main Armenian leaders. The Mamikonian family's power in particular was almost extinguished. The battle signalled the beginning of large-scale Armenian migration into the Byzantine Empire.
Background and the battle
Following the establishment of the Abbasid Caliphate, Caliph al-Mansur (r. 754-775) abolished the subsidies paid to the various Armenian princes (nakharar) and in addition imposed heavy tax duties on them. Coupled with instances of religious persecution against the majority Christian Armenian population, these measures prompted the outbreak of a major anti-Abbasid revolt in 774. The revolt was led by Artavazd Mamikonian, but gathered the direct or tacit support of most nakharar families, most notably the hitherto pro-Arab Bagratuni, while the Artsruni and Siwni families remained neutral. The rebellion spread through Armenia, including attacks against Arab tax-collectors, and the local Arab governor, al-Hasan ibn Qahtaba, was unable to contain it. The Caliph sent 30,000 Khurasanis under Amir ibn Isma'il into the province, and at the Battle of Bagrevand on 25 April 775, the nakharar suffered a decisive defeat, losing their leaders, Smbat VII Bagratuni and Mushegh VI Mamikonian. After the battle, the revolt was brutally suppressed by the Abbasids. 3
"Artavazd Mamikonian was a real person who was strategos of the
Anatolikon theme of the Byzantine Empire in 778. He is believed to be the same person who led an insurrection in Armenia in 771, and was defeated by Smbat Bagratuni, resulting in his fleeing to Georgia....
Artavazd's father may have been Hmayeak Mamikonian. See Adontz for a modern analysis. Hmayeak's father may have been another Artavazd.
This Artavazd's father may have been Hamazasp 2nd Mamikonian who is again a definite historical person. See Kirakos and Sebeos for
primary material, Cambridge Medieval History and Encycolpaedia
Britannica for respected secondary accounts.
Hamazasp's father was David or Dawith, according to Sebeos.
David's father is disputed between Vahan 2nd and a Mousegh. Vahan's father is claimed to be this same Mousegh. Mousegh's father may have been a Hmayeak. This Hmayeak's father may have been Vard, or an unnamed son of Hamazaspian.
Vard is a definite historical person. See Ghazar, Kirakos and
Sebeos. His father was general Hmayeak Mamikonian, and his mother was Dzoyk of Artsruni. General Hmayeak was quite famous, and called "blessed" by Ghazar.... His father was Hamazasp 1st and his mother was a daughter of saint Sahak, who were also parents of Vardan 2nd and Hamazaspean. Her name is given as Sahakanoysh. From saint Sahak (Isaac) back to king Tiridates, who converted to Christianity, the ancestry is based on good historical sources.
[Where I say "may have been" I mean I have found it in secondary
sources but not in contemporary or near contemporary historical