A cathedra (Latin, "chair", from Greek, καθέδρα kathédra, "seat") or bishop's throne is the seat of a bishop. It is a symbol of the bishop's teaching authority in the Catholic Church, the Orthodox Church, and the Anglican Communion churches. Cathedra is the Latin word for a chair with armrests, and it appears in early Christian literature in the phrase "cathedrae apostolorum", indicating authority derived directly from the apostles; its Roman connotations of authority reserved for the Emperor were later adopted by bishops after the 4th century. A church into which a bishop's official cathedra is installed is called a cathedral.