In 1561 Pope Pius IV (r. 1559-65) commissioned Michelangelo (1475-1564), by then in his eighties, to convert the ruins of the ancient Baths of Diocletian into the church of Santa Maria degli Angeli e dei Martiri. It was to be the master's last architectural work.
Interior
The cavernous body of the church is 90 m long, 27 m wide and 28 m high. The eight colossal monolithic columns, nearly 14 m high, are ancient Roman and made of granite; the rest of the columns in the church are made of brick and plaster and painted to look like granite!
Embedded in the floor is a meridian, the work of Francesco Bianchini, which was inaugurated by Pope Clement XI (r. 1700-20) on October 6th, 1702. It served to regulate the city's clocks until 1846.
In the middle of the 18th century, Santa Maria degli Angeli was radically restructured by Luigi Vanvitelli (1700-73), the Neapolitan architect and engineer. Vanvitelli altered the orientation of the church, moving the entrance and turning the nave into a colossal transept. He also built the choir and apse on the north east side. (Pope Pius IV is buried in a pavement tomb in the choir.)
Head of St John the Baptist by Igor Mitoraj
The beautiful bronze doors (2005) are the work of the Polish sculptor Igor Mitoraj (1944-2014), who also carved the marble head of St John the Baptist, inside the church.
The circular vestibule stands on the site of the tepidarium
St Bruno by Jean-Antoine Houdon
On the right is the tomb of the painter Carlo Maratta (1625-1713), which he designed himself; the bust (c. 1704) is by Francesco Maratta. On the left is the tomb of Salvator Rosa (1615-73); the sculpture is by Bernadino Fioriti. The statue of St Bruno (1766-67), the founder of the Carthusian Order, is by the French sculptor Jean-Antoine Houdon (1741-1828).
Great Cloister
In addition to the creation of the church, Pope Pius IV also had part of the ruins of the Baths of Diocletian converted into a Carthusian monastery. The design of its beautiful Chiostro Grande (Great Cloister) is ascribed to Michelangelo.