Basilica di Santa Maria Maggiore

A legend popular from the 14th century tells of a childless Roman patrician, John, and his wife, who in about 352, under Pope Liberius, vowed their possessions to the Virgin Mary. Snow fell on the Esquiline Hill on the night of 5 August, and, obedient to a vision they had that night, the couple built a basilica on the spot it had covered. The story is first reported after AD 1000, and may be implied in what the Liber Pontificalis says of Liberius: 'he built the basilica of his own name near the Macellum of Livia'. Long before the snow story appeared, the building was called Saint Mary of the Crib, after its relic of the manger of the Nativity: four boards of sycamore wood said to have been brought here in the time of Pope Theodore I (640–649).

The present church was raised in the years around the Council of Ephesus of 431, which proclaimed Mary Theotokos, Mother of God. It is now agreed that the present church was begun under Pope Celestine I (422–432), not under Pope Sixtus III (432–440), who consecrated it to the Virgin on 5 August 434 and left his dedication in the mosaic of the triumphal arch, Sixtus Episcopus plebi Dei, 'Sixtus the bishop to the people of God'.

The nave carried a cycle of Old Testament panels, Abraham, Jacob and Isaac on one side, Moses and Joshua on the other, of which 27 of the original 42 survive. The triumphal arch was given scenes of Christ's infancy, among them the meeting with the governor Aphrodisius, an episode drawn from the apocryphal gospels and attested in no other church.

Made pope during the plague of 590 that had killed his predecessor, Gregory the Great ordered seven processions to march through Rome chanting psalms and Kyrie eleison, and directed them to converge not on St Peter's, the traditional protector of the city, but here. The church kept the core of its original structure through the earthquake of 1348. Nicholas IV (1288–1292) added the transept and a new apse, its mosaics signed by the Franciscan Jacopo Torriti and dated 1295, showing the Coronation of the Virgin. The Romanesque campanile, built in 1375–1376 and raised under Cardinal Guglielmo d'Estouteville, archpriest from 1445 to 1483, is the tallest in Rome at about 75 metres. When the popes returned from Avignon the buildings served as a temporary papal residence, the Lateran Palace having deteriorated.

Cardinal Rodrigo Borgia, later Alexander VI, commissioned the coffered nave ceiling to a design attributed to Giuliano da Sangallo; tradition holds its gilding was made with the first gold to arrive from the Americas, given by the Spanish crown. Ignatius of Loyola celebrated his first Mass as a priest at the altar of the Nativity oratory on 25 December 1538. In 1585 Sixtus V had Domenico Fontana build a chapel of the Blessed Sacrament as a burial place for himself and for Pius V, moving Arnolfo di Cambio's crib oratory into a new crypt beneath its altar.

Paul V settled on a matching family chapel in June 1605; Flaminio Ponzio completed the structure in 1611, with the tombs of Clement VIII and Paul V on the side walls and the icon of the Salus Populi Romani above the altar. Benedict XIV had Ferdinando Fuga screen the 12th-century façade with a loggia in 1743 without damaging its mosaics; Fuga also pared the ancient nave columns to a single size and gave them matching gilt-bronze capitals.

Under the Lateran Treaty of 1929 the basilica lies in Italy rather than Vatican City while remaining property of the Holy See, which Italy is bound to protect and to grant the immunity given to foreign diplomatic headquarters. It is one of Rome's four major basilicas and forms part of a World Heritage Site listed in 1980. Archaeologists digging beneath it in 1966 found a Roman building with an imperial calendar of fasti and agricultural notes, dated to about 200 by one reading and to the 4th century by another.

The pope presides over the Feast of the Assumption here on 15 August, and the high altar is reserved to him; the King of Spain, Felipe VI, is ex officio protocanon of the chapter. Pope Francis, who called the Salus Populi Romani his great devotion and visited it before and after journeys outside the Vatican, had a tomb built next to the icon; he was buried in the side nave between the Sforza and Pauline chapels on 26 April 2025, the first pope interred outside the Vatican since Leo XIII in 1903 and the first in this basilica since Clement IX in 1669. Cardinal Rolandas Makrickas has been archpriest since 4 July 2025.