1. Building of the Church. St. Andrea stands in the site called, in the 16th century, Piazza di Siena for the presence in it of the Piccolomini palace, built by Pope Pius II (1458-1464). On this square there was also a small church dedicated to st. Sebastian, erected on the place where, according to tradition, his body was founded martyrized. In 1582 Costanza Piccolomini, Duchess of Amalfi, left her palace as inheritance to the Regular Clerics, Theatines for the construction of a church in honor of St. Andrew, the patron of Amalfi. The first project of the church is the work of the theatine architect Francesco Grimaldi. Because of the Cardinal Alfonso Gesualdo, the project was under revision by Giacomo Della Porta, personal architect of the Cardinal. Begun in 1591, the construction continued until 1608, when took the direction Carlo Maderno’s. He added to the large nave, already built, the apse and dome. The church was consecrated in 1650. Probably, in 1661, the work of the facade began by the design of Carlo Rainaldi, and was completed in 1667. Along the Rainaldi, since 1662, is reported the presence for ”reconnaissance” and assistance of Carlo Fontana.
2. The Nave. The vast interior of Sant’Andrea della Valle is a Latin cross with the arms of the transept barely protruding. The inner length of the church measures 354 Roman palms (= m. 78.41), calculated from a line, marked with the size of the Roman palm, which is 22,15is 22,15
English: World English Bible - WEB
15 Thus says the Lord, Yahweh of Armies, “Go, get yourself to this treasurer, even to Shebna, who is over the house, and say,
WP-Bible plugin cm. The height “from the floor to the top of the dome lantern, where is placed the cross with the bronze star” is 324 palms (= m. 71.78). The transept, “from one wall to another”, is 193 palms (= m 42.73). “The width of the nave, palms 75 (= 16.61), its height from the floor to the inner side of the vault is 139” palms (= m 30.78).
The nave is flanked by six intercommunicating chapels, with a rectangular floor and a domed vault. Strong fluted columns with Corinthian capitals supports the Basilica and the trabeation on top – which bears a Latin inscription from the Passio S. Andreae: + B. ANDREAS RESPONDIT: PRIMUS HOMO FOR LEGAL PREVARICATIONEM MORTEM INDUXIT … ET IF SUSCIPIENS MORTALITATEM NOSTRAM, SUAM IN NOBIS IMMORTALITATEM DONAVIT – and also a rich frame on shelves. On the frame stands the barrel vault in which the window stromes are opened. Below the archs of the chapels, we can find on each side of the basilica, the two vestibules communicating with the outside.
3. The decoration of the vault. Inside the nave, the vault, with stucco angels by Michele Tripisciano (1860-1913), was decorated by famous artists working in Rome at the beginning of the 1900s, who painted scenes referring to the mystery of the Immaculate Conception of Mary. By Salvatore Nobili we have “The Proto-Gospel”, the first announcement of salvation to the humanity, and “The Apparition of Mary”, the mother of Jesus and the new Eve, to Venerable Orsola Benincasa in Naples on February 2 of 1617 from which is derived the devotion of the scapular of the Immaculate Conception. By Virginio Monti, “The proclamation of the dogma of the Immaculate” and “The Visitation of s. Elisabetta ” and by Cesare Caroselli,” The Holy Family ” and “the Annunciation” on the entrance wall, while Silvio Galimberti executed the figures of the Apostles found in the window lunettes.
4. The floor of the basilica. During 1905, the General Father and Rector of the Church, Father Francesco di Paola, from Aragon; began to mind the replacement of the pavement, made in 1758. By the design of Paolo Medici, Stonecutter master , the works of art and the walls were taken together by Paolo Medici and the bricklayer Domenico Gilli. In perfect agreement with the contract, the floor was finished by the end of February 1907 after only three months of work.