By 750, the Mamikonians had lost Taron, Khelat, and Mouch to the Bagratids. In the 770s, the family was led by Artavizd Mamikonian, then by Mushegh IV Mamikonian (+772) and by Samuel II. The latter married his daughter to Smbat VII Bagratuni, constable of Armenia. His grandson Ashot Msaker ("the Carnivorous") became forefather of Bagratid rulers of Armenia and Taron. The final death-blow to the family's power came in the mid-770s, with the defeat and death of Mushegh VI Mamikonian at the Battle of Bagrevand against the Abbasids. In its aftermath, Mushegh's two sons took refuge in Vaspurakan and were murdered by Merouzhan II Artsruni, and his daughter was married off to Djahap al-Qais, a tribal chief who settled in Armenia and seized part of the former Mamikonian lands and legalized it by marrying the daughter of Mushegh VI, the last living Mamikonian prince. This marriage created the Kaysite Dynasty of Arminiya centered in Manzikert, the most powerful Muslim Arab emirate in the Armenian Highlands region, and thus ending the existence of the Mamikonian line in Armenia. Only secondary lines of the family survived thereafter, both in Transcaucasia and in Byzantium. Even in their homeland of Tayk, they were succeeded by the Bagratids. One Kurdik Mamikonian was recorded as ruling Sasun c. 800, where the Surb Karapet Monastery and family seat was. Half a century later, Grigor Mamikonian lost Bagrevand to the Muslims, reconquered it in the early 860s and then lost it to the Bagratids, permanently. After that, the Mamikonians pass out of history. After their disastrous uprising of 774–775, some of the Mamikonian princes moved to the Georgian lands. The latter-day Georgian feudal houses of the Liparitids-Orbeliani and Tumanishvili are sometimes surmised to have been descended from those princes. Several scholars—most notably Cyril Toumanoff and Nicholas Adontz—have suggested a Mamikonian origin for a number of leading Byzantine families and individuals, beginning with the usurper Phocas in the early 7th century, emperor Philippikos Bardanes, the general and usurper Artabasdos in the mid-8th century, and the families of men like Alexios Mosele or Empress Theodora and her brothers Bardas and Petronas in the 9th century.