Exonarthex

The narthex is an architectural element typical of early Christian and Byzantine basilicas and churches consisting of the entrance or lobby area, located at the west end of the nave, opposite the church's main altar. Traditionally the narthex was a part of the church building, but was not considered part of the church proper.

In early Christian churches the narthex was often divided into two distinct parts: an esonarthex (inner narthex), between the west wall and the body of the church proper, separated from the nave and aisles by a wall, arcade, colonnade, screen or rail, and an external closed space, the exonarthex (outer narthex), a court in front of the church facade delimited on all sides by a colonnade as in the first St. Peter's Basilica in Rome or in the Basilica of Sant'Ambrogio in Milan. The exonarthex may have been either open or enclosed, with a door leading to the outside as in the Byzantine Chora Church.

By extension, the narthex can also denote a covered porch or entrance to a building.

The word comes from narthex (Medieval Latin from Classical Greek narthex νάρθηξ "giant fennel, scourge") and was the place for penitents. In Modern Greek narthekas (νάρθηκας) no longer has this meaning and is either the porch of a church, as English, or the brace of a sprained wrist or sling of a broken arm. In English the narthex is now the porch outside the church at the west end, formerly it was a part of the church itself.

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