An Armenian of the Chalcedonian profession, this astute politician is well known from several oriental sources. Gabriel became duke of Melitene under the authority of Philaretos Brachamios, and he withstood the incursions of the Turks until finally capitulating in 1102. After that date he proved his skill as a diplomat by maintaining his ties with the Empire, receiving subsequently the dignity of curopalates from the Emperor, while at the same time recognising the sovereignty of the Grand Sultan of the Seljuks, Malik Shah. He even sent his wife on a mission to Baghdad to obtain recognition of his own position from the Sultan. Another seal of Gabriel, of around 1086, formerly in the Zacos collection (Z.II, 464), and now in the Bibliothque National, gives Gabriel the titles of curopalates, duke, and emir.