Pius IV, Giovanni Angelo de Medici consecrated the Church of S. Maria degli Angeli on 5 August 1561 . He transferred the title of Saint Ciriaco to the Baths and enabled the Carthusian monks to worship here officially. They had occupied a place in the Church since 1091. Pius IV died on 19 December 1565 and was buried for a while in St. Peter's. In 1583 he was transferred to his final resting place in the presbytery of S. Maria degli Angeli. He had arranged for Michelangelo to create this for him from the ruins of the Diocletian baths.

A memorial of his funeral can still be seen at the bottom of the left hand side of the apse in the Church. It was built under the supervision of 3 cardinals one being the Pope's cousin Antonio Serbelloni who was Cardinal Priest of this titular Church in 1565. The other cardinals were nephews of Pius, Marco Sittico Altemps who became incumbent of the Church in 1577 and St Carlo Borromeo. St Carlo's villa was located in the Baths. It had been purchased by the French cardinal Du Bellay and then handed to the Carthusians. St Carlo returned to Rome from Milan in 1575 for the Holy Year. He resided in the Carthusian dwelling at Santa Maria Degli Angeli.

We cannot forget cardinal Federico Borromeo (from Manzoni's ‘The Betrothed') who was Cardinal Priest for 38 years from 1593 to 1631. A stone plaque located in the parochial house commemorates his ordination as Archbishop of Milan on 11 June 1595 by Clement VIII, Ippolito Aldobrandini (1595-1605) which took place in this very Basilica.

“The memorial of Pius IV is simple from an artistic point of view and mirrors the austerity of the times. The white marble slab is flanked by columns with ornamental decorations above including a cherub; the memorial bears the crest of keys and a tiara. In the upper part of the columns one can see a merest hint of Michelangelo but in the penultimate decade of the century the work was attributed to Giacomo Del Duca and it is not difficult to see why given that logically there was no other candidate the 3 originators of the work could have approached. According to a document discovered by A Schiavo the execution of the project was entrusted to the Florentine sculptor Alessandro Cioli on 20 February 1582 (Guglielmo Matthiae).”

In front there is another memorial identical to the one of Pius IV except there is no cardinal's crest and is dedicated to his cousin Antonio Serbelloni.

In 1801 Pius VII Barnaba Chiaramonti (1800 – 1823) united the memorial of S Bartolomeo di Trisulti (Fr) to the carthusians of S. Maria Degli Angeli. But this decision was then repealed by Pio XII Eugenio Pacelli (1939 – 1958) and it was passed to the Cistercians of Casamari (Fr) in 1940.

The Carthusians of Santa Maria degli Angeli were forced to abandon the monastery 3 years after the unification of Italy and following law no. 1402 of 19 June 1873 which suppressed the ecclesiastical estate. The magnificent monastery was at first used as a military store for the French troops but then the Italian government transformed into a national archaeological museum. Custody of the Church was taken by the Minimi of S. Francesco da Paola and then by the Diocese of Rome.

On 30 August 1884 the Cardinal Vicar Lucido Parrocchi asked Leone XIII Vincenzo Gioacchino Pecci (1878 – 1903) if the custody of the carthusians parish of S Bernardo to the Baths could be transferred to the church of Santa Maria Degli Angeli . The Pontiff granted his approval but the Cardinal Vicar did not issue a decree.

The area was inferred entirely from the parish of S. Bernardo to the Baths which the Pontif himself had suppressed.

St. Pio X Giuseppe Sarto (1903 – 1914) with an apostolic letter dated 9 November 1906 “Susceptum Deo inspirante” awarded to Santa Maria Degli Angeli parish status as well as the income from S Giovanni dei Fiorentini. And that is how Santa Maria became a parish Church and this is commemorated by a marble stone which can be found in the present chapel of S. Teresa together with a bronze bust by Michelangelo and another by the Sicilian Don Antonio Lo Duca, proponent of the angels. There is a marble decoration of Lo Duca above which there is the following inscription: “In the year of 1971, marking the 75th anniversary of Santa Maria as a parish Church by will of S Pio X in 1906, the faithful of Santa Maria Degli Angeli, the Sicilians resident in Rome and the citizens of Cefalù, wanted to dedicate this marble stone to the Sicilian Antonio Lo Duca here buried, who with the help of S Filippo Neri and S Carlo Borromeo, persuaded Pio IV in 1561 to commission Michelangelo to transform the Diocletian baths built with the sweat and blood of slaves and Christian martyrs into the Church dedicated to S Maria Regina of the Angels and of the Martyrs.”

On 22 May 1910 Pio X nominated Monsignor Giuseppe Giovannelli as first Parish priest. He also bestowed upon the Parish the Crucifix which can be seen in the Aula Magna of the Auditorium.

On 20 July 1920 Benedetto XV Giacomo della Chiesa (1914-1922) elevated the Church to status of a minor basilica with his apostolic letter, “Ad perpetuam rei memoriam. Titulum Sancti Ciriaci in Thermis...” The ancient church of S Ciriaco was demolished to make way for the imposing building of the Finance Ministery in Via XX Settembre.

On 27 June 1920 the same Pope crowned the venerated image of the Virgin in the Vatican which can now be found in the centre of the apse. This image was created by Antonio Lo Duca himself. Above this picture Pio IV had arranged for the following inscription to be added: “Quod fuit idolum nunc templum est Virginis. Auctor est Pius ipse Pater Daemones aufugite.” (This temple which has already been assigned to idolatry was consecrated to the Virgin by will of Pope Pio. Demons get away).

The marriage of the Prince of Naples (future king of Italy , Vittorio Emanuelle III) and princess Elena of Montenegro was celebrated in the basilica on 24 October 1896 . From this point onwards Santa Maria degli Angeli became the official Church of the Italian State .

During the pontificate of Pope Paolo VI Giovanni Battista Montini (1963 – 1978), when Giuseppe Saragat was President of the Republic and when Monsignor Vittorio di Paola (1955-1983) was parish priest the following works were undertaken in the Parish as a perpetual reminder to commemorate the ‘Centenary of Rome as Capital':

• the living quarters of the titular cardinal, of the clergy, of the nuns and of the personnel;
• the side entrance in Via Cernaia with it's square dedicated to S Pio X, the parochial reception hall and rooms for the various Associations;
• rooms dedicated to Pio IV, to Michelangelo, to the priest Antonio Lo Duca, to S Carlo Borromeo, to S Filippo Neri;
• the flooring in the round Chamber of the passageway to the calidarium, the rooves, the balconies, the windows in the Church, the wiring of the bells and and the antique clock.

The following parishes are close neighbours of Santa Maria Degli Angeli: S. Camillo De Lellis, S. Cuore di Gesu a Castro Pretorio, S. Maria Maggiore and Santi Vitale e Compagni Martiri in Fovea. It also forms part of the town hall, Settore Centro, Rione Castro Pretorio and the Prefecture.

The following is a list of priests who have been at the Parish from it's beginning: Monsignor Giuseppe Giovannelli (1910 – 1943), Monsignor Cosimo Bonaldi (1944 – 1955), Monsignor Vittorio di Paola (1955 – 1983), Monsignor Vincenzo Pezzella (1983 – 1990), Monsignor Renzo Giuliano (1991 to date).