San Sebastiano fuori le mura (Saint Sebastian outside the walls) was built originally in the first half of the 4th century. The basilica is dedicated to St. Sebastian, a popular Roman martyr of the 3rd century. 'Fuori le mura' refers to the fact that the church is built outside the Aurelian Walls, and is used to differentiate the basilica from the church of San Sebastiano al Palatino on the Palatine Hill.
The church is built above one of Rome's famous catacombs or underground cemeteries, and in fact the word 'catacomb' comes from this site. According to the founding tradition, in 258, during the Valerian persecutions, the catacombs were temporarily used as place of sepulture of two other saints martyred in Rome, Peter and Paul, whose remains were later transferred to the two basilicas carrying their names: whence the original dedication of the church, Basilica Apostolorum ('Basilica of the Apostles'). The dedication to Sebastian dates to the 9th century.
Sebastian's remains were moved here around 350. They were transferred to St. Peter's in 826, fearing a Saracen assault: the latter, in fact, materialized, and the church was destroyed. The building was refounded under Pope Nicholas I (858–867), while the martyr's altar was reconsecrated by Honorius III (1216–1227), by request of the Cistercians, who had received the place. In the 13th century the arcade of the triple nave was walled in.
The current edifice is largely a 17th-century construction, commissioned by Cardinal Scipione Borghese in 1609 from Flaminio Ponzio and, after Ponzio's death in 1613, entrusted to Giovanni Vasanzio, who completed it.
The statue of St Sebastian at the altar in the first chapel on the left is by Giuseppe Giorgetti. The Chapel of Relics, located directly across the nave, houses a stone allegedly imprinted with the footprints of Jesus related to the episode of 'Quo vadis?' in the apocryphal Acts of Peter; and one of the arrows which struck St Sebastian together with part of the column to which he was tied during the martyrdom. Noteworthy is the Albani Chapel (built 1716) and designed by Carlo Maratta, Alessandro Specchi, Filippo Barigioni and Carlo Fontana; commissioned by Pope Clement XI; and dedicated to Pope Fabian. Fabian had been Bishop of Rome during the persecution of Decius. Flanking the altar, busts of Saints Peter and Paul by Nicolò Cordier recall the first dedication of the basilica.
References:The Church of St Donatus name refers to Donatus of Zadar, who began construction on this church in the 9th century and ended it on the northeastern part of the Roman forum. It is the largest Pre-Romanesque building in Croatia.
The beginning of the building of the church was placed to the second half of the 8th century, and it is supposed to have been completed in the 9th century. The Zadar bishop and diplomat Donat (8th and 9th centuries) is credited with the building of the church. He led the representations of the Dalmatian cities to Constantinople and Charles the Great, which is why this church bears slight resemblance to Charlemagne's court chapels, especially the one in Aachen, and also to the Basilica of San Vitale in Ravenna. It belongs to the Pre-Romanesque architectural period.
The circular church, formerly domed, is 27 m high and is characterised by simplicity and technical primitivism.