According to tradition, the martyr St. Miniatus, who was suffered during the persecution of Decius in the 3rd century, was buried on the hill where the church bearing his name now stands. It was the idea of the bishop Hildrebrand to build the basilica, together with the adjoining Benedictine monastery, on the site where it was believed that the relics of the saint (today preserved in the crypt of the church) were found.

Work was begun in 1018 and was completed about 1207. The new church which was built on the site of an earlier church reflects the various stages of its construction in its different parts, from the crypt to the elaborate marble floor of the nave. The beautiful façade, of green and white marble in the Tuscan manner, has a blind colonnade in the lower register. The mosaic on the pediment showing Christ in benediction between the Virgin and St. Miniatus dates from the beginnnig of the 13th century. The polychrome marble decoration of the facade is also a feature of the interior, dominated by the raised presbytery.

The church, which is one of the masterpieces of the Tuscan Romanesque, combines a basilical plan of classical origin with typically romanesque elements; some of the capitals are Roman and others are romanesque. The oldest decoration is the mosaics and the marble inlay work, of which the most important is the central part of the pavement. This area, which retains its original decoration, shows interesting figurative motifs, enriched with symbolic significance. The beautiful Zodiac, which is originally a pagan motif, here assumes a Christian symbolic value, according to some, by its subdivision into twelve signs which allude to the twelve Apostles. The area of the apse is also richly decorated, with superb marble inlays on the altar, the enclosure and the pulpit, and is dominated by the beautiful mosaic bearing the date 1297; it depicts Christ in benediction between the Virgin, St. Miniatus, the symbols of the Evangelists and the kneeling donor, and it is characterised by a technique making use of strong chromatic contrast.

The sacristy is decorated by a cycle of frescoes of Episodes from the life of Saint Benedict by Spinello Aretino (c. 1387), commissioned by Benedetto degli Alberti. In the chapel of the Crucifix, the little tempietto at the end of the nave, to house the famous Crucifix which supposedly inclined its head to St. John Gualbert who had pardoned the murderer of his brother, the church received several new masterpieces. In 1447 Piero de’ Medici commissioned Michelozzo (or, according to another theory, Alberti) to build the chapel of the Crucifix, the little tempietto at the end of the nave, to house the famous Crucifix which supposedly inclined its head to St. John Gualbert who had pardoned the murderer of his brother. The eagles are the emblem of Calimala, the Merchants’ Guild that from the 13th century onwards was responsible for the maintenance of the church.

The Chapel of the Cardinal of Portugal in the left aisle constitutes an extraordinary gem of the Renaissance having preserved a combination of architecture, painting and sculpture as it was originally conceived: it was built to contain the tomb of James of Lusitania, Cardinal of Portugal, who died very young in Florence in 1459. Several of the major artists of the Renaissance worked in this chapel, having been selected and commissioned by the Cardinal’s uncle. Possibly designed by Antonio Manetti, with the later involvement of Rossellino, it is a kind of jewellery box adorned with painting, stone and coloured marble. It required the collaboration of Luca della Robbia for the ceiling in glazed terracotta with the Cardinal Virtues (1461), and Antonio Rossellino for the magnificent Tomb with the effigy of the Cardinal (1461-66). The painted decoration was entrusted in part to Alesso Baldovinetti, who painted the Eight Prophets in the pendentives and the Evangelists and Doctors of the Church in the lunettes as well as the Annunciation. He was succeeded by the Pollaiolo brothers, who painted the two curtain-drawing Angels on either side of the altarpiece depicting St. Vincent, St. James and St. Eustace, which is also a work by the same artists (now replaced by a copy; the original is in the Uffizi).