Sant'Angelo was constructed in the mid-16th century by the Spanish general and Governor Milan Ferrante Gonzaga, over an edifice already existing in 1418, in replacement of the eponymous one, which had been destroyed to build the new walls. The design was by Domenico Giunti. The small bell tower was added in 1607, while the façade was finished only in 1630, in late-Mannerist or early-Baroque style. The church is one of the few in the city which was not restored in 'neo-medieval' style during the 19th century.
It has a single nave with side chapels and barrel vault, a transept and a deep presbytery. Artworks include works by Gaudenzio Ferrari, Antonio Campi, Morazzone, Simone Peterzano, Ottavio Semino, Camillo Procaccini and Giulio Cesare Procaccini. The triumphal arch has a frescoes with a solemn Incoronation of Mary by Stefano Maria Legnani.
In the transept is the tomb of Blessed Beatrice Casati, the wife and widow of Francino Rusca, the Earl of Locarno. She raised four children -- three sons and one daughter, the latter of whom placed this monument to their mother -- and was a devout member of the Franciscan tertiaries. She died in 1490.
References:The Clementinum is a historic complex of buildings in Prague. Until recently the complex hosted the National, University and Technical libraries, the City Library also being located nearby on Mariánské Náměstí. The Technical library and the Municipal library have moved to the Prague National Technical Library at Technická 6 since 2009. It is currently in use as the National Library of the Czech Republic.
Its history dates from the existence of a chapel dedicated to Saint Clement in the 11th century. A Dominican monastery was founded in the medieval period, which was transformed in 1556 to a Jesuit college. In 1622 the Jesuits transferred the library of Charles University to the Klementinum, and the college was merged with the University in 1654. The Jesuits remained until 1773, when the Klementinum was established as an observatory, library, and university by the Empress Maria Theresa of Austria.