Cathedra is a Latin word for throne. Originally, it designates any chair with armrests ; in ancient times, this was commonly seen as a sign of authority. In the Roman Catholic Church, the word came to be associated with the bishop's throne, which stands in the main church of the diocese - hence the name cathedral for this church. The term has to some extent been preserved in the Anglican and Episcopalian churches, and in a lesser degree in some Lutheran churches. It does, however, live on in many languages and different churches through the word cathedral.
The traditional place for the throne was in the apse, behind the high altar. In the Middle Ages, it became more common to move it to one side. As altars more often came to be placed against the wall of the apse, this practice became the standard. In later years, it can again be found behind the altar, as more churches adopt a free-standing altar.
In the Roman Catholic Church, the term is also used to designate certain pronouncements from the pope. According to dogma, the pope's statements are infallible when spoken ex cathedra, meaning from the throne of Saint Peter. It is beyond the scope of this article to define ex cathedra statements. The word is also used in one other context which is specific to catholicism, namely the feast Cathedra Petri , the Throne of Peter. Celebrated on 22 February, it is an expression of unity with the pope and thanksgiving for the mission of Saint Peter.