Apse
Semicircular recess covered with a hemispherical vault or semi-dome

In architecture, an apse (pl.: apses; from Latin absis, 'arch, vault'; from Ancient Greek ἀψίς, apsis, 'arch'; sometimes written apsis; pl.: apsides) is a semicircular recess covered with a hemispherical vault or semi-dome, also known as an exedra. In Byzantine, Romanesque, and Gothic Christian church (including cathedral and abbey) architecture, the term is applied to a semi-circular or polygonal termination of the main building at the liturgical east end (where the altar is), regardless of the shape of the roof, which may be flat, sloping, domed, or hemispherical. Smaller apses are found elsewhere, especially in shrines.
01Definition
An apse is a semicircular recess, often covered with a hemispherical vault. Commonly, the apse of a church, cathedral or basilica is the semicircular or polygonal termination to the choir or sanctuary, or sometimes at the end of an aisle.
Smaller apses are sometimes built in other parts of the church, especially for reliquaries or shrines of saints.

02History
The domed apse became a standard part of the church plan in the early Christian era.
Sources and credits
This article is adapted from the Wikipedia article “Apse”, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.
Images, from Wikimedia Commons:
- Basilica of Sant'Apollinare in Classe - Mosaic.jpg by Gleb Simonov, CC0
- Apse.png by Unknown author, CC BY-SA 3.0
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