Jac'obites, Christians in the East, who were united by a Syrian monk, Jacobus Barbadaeus (578), during the reign of Justinian, into a distinct religious sect. The Jacobites, so styled from their founder, number now about 80,000. They are governed by the patriarch of Antioch, whose appointment must be confirmed by the sultan, and who has under him eight metropolitans and three bishops. The metropolitan of Jerusalem ranks higher than the others, and with the patriarch he lives at the monastery near Mardin. The doctrine of the single nature of Christ is common to them and to the Copts and Abyssinians; but in other respects they differ little from the orthodox Greek Church.