Katholikon

A Katholikon ( _el. Καθολικόν) is the major temple (church building) of a monastery, or diocese in the Eastern Orthodox Church. The name derives from the fact that it is (usually) the largest temple where all gather together to celebrate the major feast days of the liturgical year. At other times, the smaller temples or chapels would be used. In Russia, it is common for a katholikon to have a smaller church in the basement which can be more easily heated in the winter.

A katholikon may have special architectural features in it, such as a kathedra (episcopal throne), or both an "esonarthex" (inner-narthex) and "exonarthex" (outer narthex), used for special services such as during Holy Week or the Paschal vigil.

The word katholikon is often translated into English as cathedral; however, unlike in Western Christianity an Eastern Orthodox diocese may have more than one cathedral. In addition to a bishop's primary cathedral, other important churches may be elevated to the dignity of cathedral, without the bishop actually being resident there. The rector of such churches will usually be an Archpriest or Protopresbyter.