Santi Apostoli is a 15th century minor basilica, parish and titular church on ancient foundations in the rione Trevi (II), next to the Palazzo Colonna. The dedication of the church is to the Twelve Apostles, and the official name is
Santi XII Apostoli. It is in the care of the Conventual Franciscans.
For reference, a plan of the church is available
here.
The first church on the site may have been founded in the time of Pope Julius I (R. 337-352), who erected it in the ancient barracks of the Vigiles in about the year 340. However, the first church we have certain knowledge about was founded by Pope Pelagius I (R. 556-561) in commemoration of the victory over Totila and the Ostrogoths. It was completed and consecrated by his immediate successor John III (R. 561-574), and dedicated to the Apostles St James and St Philip.
The Basilica was neglected during the 14th century Avignon papacy. In 1348 the church was severely damaged by an earthquake, and had to be abandoned. It was rebuilt in 1417 by Pope Martin V whose family, the Colonnas, owned the surrounding area. It was on this occasion that it was dedicated to the Twelve Apostles. The church was later embellished by the Byzantine Cardinal Bessarion (1403-1474), but the church did not regain real significance until Pope Pius II (R. 1458-1464) gave it to the Minori Conventurali (Black Friars Minor).
The façade and two-story entrance portico was rebuilt in at the end of the 15th century by
Baccio Pontelli. In the main apse was an enormous fresco by
Melozzo da Forlì, regarded as his masterpiece and painted in 1480. Pontelli's design for the portico was changed when
Carlo Rainaldi walled up the arches on the upper level, inserted windows in the Baroque style and added the statues of
Christ and the Apostles to the parapet around the year 1665.
A drastic new restoration took place under Pope Clement XI (R. 1700-1721), carried out by a team of architects led by
Carlo Fontana and his son
Francesco. The (probably damaged) apse fresco by Melozzo was tragically removed in 1711. Further restoration became necessary when a fire severely damaged the building in 1872. The restoration in 1873 dug out the ancient crypt. In this restoration, the ancient high altar of the crypt was discovered with the relics of the apostles Philip and James still in place.