Mamikonian, son of Artavazd and sparapet of Armenia, was ordered by King Khosrov III to exterminate two feuding noble families, the Manavazians and the Ordunis. Vache also successfully defended Armenia against Sanesan, the invading king of the Maskuts, slaying the latter in a battle near Oshakan Fortress and receiving new holdings as reward. He later fell in battle against the Persians and was succeeded as sparapet by his son Artavazd, who was a child at the time, since "no other adult could be found in that clan." This episode and others in Pavstos' History illustrate the nature of the office of sparapet as the exclusive and hereditary possession of the Mamikonian clan. The family reappears in chronicles in 355, during the reign of Arshak (Arsaces) II. At that point the family chief was sparapet Vasak Mamikonian. When Arshak II sided with the Sasanian Empire against the Eastern Roman Empire, Vasak raided Roman lands for six years. After Arshak switched to the Roman side against Persia, Vasak Mamikonian commanded the Armenian defense, winning a series of victories against Shapur II's forces, although he was unable to capture the rebellious Armenian nobleman Meruzhan Artsruni. After years of warfare, multiple other Armenian lords defected to the Persian side, including Vasak's renegade brother Vahan Mamikonian. Vasak was later flayed alive after being lured to Persia for peace negotiations together with Arshak II. Shapur laid waste to Armenia and installed Meruzhan Artsruni and Vahan Mamikonian as governors (according to Pavstos, Vahan was later killed by his own son, Samuel). Vasak was succeeded as sparapet by his son Mushegh I Mamikonian, who restored Arshak's heir, Pap, to the throne c. 367/370 with the support of an imperial army sent by the emperor Valens. Mushegh drove the Persians out of Armenia and brutally punished the provinces that had revolted against the Arsacid monarchy, restoring the kingdom's former borders. Following Pap's murder in 374, Mushegh acted as regent for the new king Varazdat (Varasdates). Varazdat attempted to free himself of Mamikonian tutelage by ordering Mushegh's murder and replacing him as sparapet with a non-Mamikonian noble, Smbat Saharuni.On this event, the family leadership passed to Mushegh's brother, Manuel Mamikonian, who had formerly been kept as a hostage in Persia. The Mamikonians at once broke into insurrection and routed Varazdat and Saharuni at Karin. Varazdat fled abroad and Manuel installed the two underage sons of Pap, Vagharshak (Vologases) and Arshak