Cathedra

A cathedra (Latin, "chair", from Greek, kathedra, "seat") or bishop's throne is the chair or throne of a bishop. It is a symbol of the bishop's teaching authority in the Catholic Church and the Orthodox Church, and has in some sense remained such in the Anglican Communion and in Lutheran 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.

Read more about Cathedra:  Cathedra Petri, Chair of St. Augustine, Ex Cathedra, Placement