Origen of Alexandria (185 AD–ca. 254) wrote:
"In Bethlehem the cave is pointed out where He was born, and the manger in the cave where He was wrapped in swaddling clothes. And the rumor is in those places, and among foreigners of the Faith, that indeed Jesus was born in this cave who is worshipped and reverenced by the Christians." (Contra Celsum, book I, chapter LI).
The first basilica on this site was begun by Saint Helena, the mother of the Emperor Constantine I. Under the supervision of Bishop Makarios of Jerusalem, the construction started in 327 and was completed in 333. That structure was burnt down in the Samaritan Revolt of 529.
The current basilica was rebuilt in its present form in 565 by the Emperor Justinian I. When the Persians under Chosroes II invaded in 614, they unexpectedly did not destroy the structure. According to legend, their commander Shahrbaraz was moved by the depiction inside the church of the Three Magi wearing Persian clothing, and commanded that the building be spared. The Crusaders made further repairs and additions to the building during the Latin Kingdom of Jerusalem with permission and help given by the Byzantine Emperor, and the first King of Jerusalem was crowned in the church. Over the years, the compound has been expanded, and today it covers approximately 12,000 square meters. The church was one of the direct causes for French involvement in the Crimean War against Russia.
The church is administered jointly by Roman Catholic, Greek Orthodox and Armenian Apostolic authorities. All three traditions maintain monastic communities on the site.
The structure is actually a combination of two churches, with a crypt beneath—the Grotto of the Nativity—where Jesus is said to have been born:
• The main Basilica of the Nativity is maintained by the Greek Orthodox Patriarchate of Jerusalem. It is designed like a typical Roman basilica, with five aisles (formed by Corinthian columns) and an apse in the eastern end, where the sanctuary is. The church features golden mosaics covering the side walls, which are now largely decayed. The basilica is entered through a very low door, called the "Door of Humility." The original Roman style floor has since been covered over, but there is a trap door in the modern floor which opens up to reveal a portion of the original mosaic floor. The church also features a large gilded iconostasis, and a complex array of lamps throughout the entire building. The wooden rafters were donated by King Edward IV of England. The same king also donated lead to cover the roof; however, this lead was later taken by the Turks, who melted it down for ammunition to use in war against Venice. Stairways on either side of the Sanctuary lead down by winding stairs to the Grotto.
• The adjoining Church of St. Catherine, the Roman Catholic Church, was built in a more modern Gothic revival style, and has since been further modernized according to the liturgical trends which followed Vatican II. This is the church where the Latin Patriarch of Jerusalem celebrates Midnight Mass on Christmas Eve. Certain customs still observed in this Midnight Mass predate Vatican II, but must be maintained because the "status quo" (the customs, rights and duties of the various church authorities that have custody of the Holy Places) was legally fixed by a firman in 1852, under the Ottoman Empire, that is still in force to this day.
• The Bas-relief of the Tree of Jesse is a large work by well-known religious sculptor Czesaw Dwigaj which was recently incorporated into the Church of St. Catherine as a gift of Pope Benedict XVI during his trip to the Holy Land in 2009. Measuring in at 3.75 by 4 metres (12.3 by 13.1 ft), its corpus represents an olive tree figuring as the Tree of Jesse diplaying Christ`s lineage from Abraham through St. Joseph along with other biblical motifs. Situated along the passage used by pilgrims making their way to the Grotto of the Nativity, the bas relief also incorporates symbolism from the Old Testament. The upper portion is dominated by a crowned figure of Christ the King in an open armed pose blessing the Earth.
• The Grotto of the Nativity, an underground cave located beneath the basilica, enshrines the site where Jesus is said to have been born. The exact spot is marked beneath an altar by a 14-pointed silver star set into the marble floor and surrounded by silver lamps. This altar is denominationally neutral, although it features primarily Armenian Apostolic influences. Another altar in the Grotto, which is maintained by the Roman Catholics, marks the site where traditionally Mary laid the newborn Baby in the manger.
• Numerous Chapels are found in the compound as well, including the Chapel of Saint Joseph, commemorating the angel`s appearance to Joseph, commanding him to flee to Egypt (Matthew 2:13); the Chapel of the Innocents, commemorating the children killed by Herod (Matthew 2:16-18); and the Chapel of Saint Jerome, where traditionally he translated the Bible into Latin (the Vulgate).
• Manger Square, a large paved courtyard in front of the Church, is the site where crowds gather on Christmas Eve to sing Christmas carols.