In the early 690s, Armenia was in turmoil, as the country was being disputed between the Byzantine Empire and the Umayyad Caliphate: taking advantage of the civil war of the Second Fitna in the Caliphate, the Byzantine emperor Justinian II had invaded Armenia and installed his own candidate, Nerses Kamsarakan, as its presiding prince, while Kamsarakan' predecessor, Ashot II Bagratuni, was killed in 690 fighting against a retaliatory Arab invasion.
[3][6] When the Umayyads, after the end of the civil war, returned in force to Armenia in 693 under Muhammad ibn Marwan, Smbat defected to their side, and even had the captured Byzantine soldiers mutilated and executed, in vengeance for his father.
[10] He gathered his followers north of Mount Ararat, including the prince of Vaspurakan, also named Smbat, and Vard Rhstuni, whose father Theodore had played a central role in the submission of Armenia to the Arabs in the 650s.
The 8,000-strong Umayyad garrison at Nakhchivan pursued them, but the Arabs, unaccustomed to the harsh winter conditions, were defeated with heavy loss near Vardanakert; reportedly, only 300 of them survived the battle and the cold to reach safety.
[13] At the head of a Byzantine force, Smbat invaded Armenia, but was defeated and had to retreat, establishing himself this time at the Poti on the Black Sea coast, likely an indication that the Arabs menaced his former base.
[15] According to the historian Joseph-François Laurent, Smbat was the "most typical example" of the tendency of the Armenian princes to switch sides between Byzantium and the Caliphate, whenever they quarreled with either one of the two great powers of the region.