Gabras or Gavras (Greek: Γαβρᾶς), feminine form Gabraina (Γάβραινα), is the surname of an important Byzantine aristocratic family, which became especially prominent in the late 11th and early 12th centuries as the semi-independent and quasi-hereditary rulers of Chaldia.
The Gabrades are attested for the first time in the late 10th century, when Constantine Gabras participated in the revolt of Bardas Skleros. The general Theodore Gabras captured Trebizond and ruled it and the theme of Chaldia as a virtually autonomous state (ca. 1081–1098). He was celebrated for his martial exploits, and was later venerated as a saint in the region. His son, Constantine Gabras, also became governor of Chaldia (ca. 1119–1140) and ended up ruling it as a quasi-independent prince. Several members of the family entered service with the Seljuk Turks in the 12th and 13th centuries, and in the 14th century, several Gabrades are attested in administrative positions in Byzantium, most notably the official and scholar Michael Gabras, known for his extensive correspondence with the main Byzantine literary and political figures of his day, and his brother John. A branch of the family also became rulers of the Principality of Theodoro in the Crimea.
The family first appears in the northeastern corner of the Byzantine world, the province of Chaldia, centred on Trebizond. The family's ethnic origin is unknown. Some scholars like Alexander Vasiliev and Alexander Kazhdan suggested an Armenian origin, as with many other aristocratic families of the time, but the surname "Gabras" is neither Armenian nor Greek. Persian and Aramaic origins for the name have been suggested, including a suggestion by Konstantinos Amantos that it is a corruption of the name "Gabriel". The historian Anthony Bryer, however, considers more likely that the name is a cognate of the Arabic kafir, Persian gabr or Turkish gavur, terms meaning "infidel" or "unbeliever", which is appropriate for the Christian–Muslim borderlands where the Gabrades first appear. It seems that the Gabrades arose from the Inner Pontus, a region with its own distinct identity: a mountainous area, it was scarcely affected by Hellenization and preserved a traditional and archaic societal structure, with tiny lordships centred on mountain strong-holds.