Cathedra

The term appears in early Christian literature in the phrase cathedrae apostolorum, indicating authority derived directly from the apostles.

[2][3] The doctrine of papal infallibility, the Latin phrase ex cathedra (literally, "from the chair") was proclaimed at the First Vatican Council by Pius IX in 1870 as meaning "when, in the exercise of his office as shepherd and teacher of all Christians, in virtue of his supreme apostolic authority, the Bishop of Rome defines a doctrine concerning faith or morals to be held by the whole Church.

It is a Byzantine throne with framed fragments of acacia wood, encased in the oak carcass and reinforced with iron bands.

Greater than life-sized sculptures of four Doctors of the Church form an honour guard: St. Ambrose and St. Athanasius on the left, and St. John Chrysostom and St. Augustine on the right.

A fifth- or sixth-century bishop's throne decorated with elaborate ivory carving is preserved in the sacristy of the cathedral at Ravenna.

Canterbury Cathedral, in which the cathedra is housed, maintains that the chair was once part of the furnishings of the shrine of St. Thomas Becket, since dismantled.

He is seated on the throne in the quire as Diocesan Bishop, in the chapter house as titular abbot, and in St. Augustine's chair as Primate of All England.

The early Christian bishop's throne, or cathedra, stood in an elevated position behind the altar, near the wall of the apse.

The cathedra in cathedrals built or renovated after Vatican II is sometimes placed behind the altar, as in ancient Roman basilicas.

Eastern Orthodox and Byzantine Rite Catholic churches have a throne for the bishop in the apse behind the holy table, with seats for the priests (Greek: synthranon) arranged to either side.