Francesco Borromini (Bissone near Lugano, Switzerland, September 25, 1599 - Rome, Italy, August 3, 1667) was a Baroque architect, and rival of Gian Lorenzo Bernini.
Son of stone mason Giovanni Domenico Castelli, Borromini began his career as a stone mason himself, and soon moved to Milan to study and practice this activity. When in Rome (1619) he changed his name (from Castelli to Borromini) and started working for Carlo Maderno, his distant relative, at St. Peter's. When Maderno died in 1629, he joined the group of Gian Lorenzo Bernini, with whom he completed Maderno's Palazzo Barberini.
In 1634 he had his first personal work, the reconstruction of the church of San Carlo alle Quattro Fontane (some authors say it is here that he changed his name).
Borromini's works include:
San Carlo alle Quattro Fontane
Sant'Agnese in Agone
Sant'Ivo alla Sapienza
San Giovanni in Laterano
Cappella Spada, San Girolamo della CaritÓ (however, it is uncertain if Borromini really is the architect of the chapel)
Sant'Andrea delle Fratte
Oratorio dei Filippini
Collegio de Propaganda Fide
Santa Maria dei Sette Dolori
San Giovanni in Oleo (restoration)
Palazzo Giustiniani (with Carlo Fontana)
Santa Lucia in Selci (restoration)
For Sant'Agnese in Agone, he reverted the original plan of Girolamo Rainaldi (and his son Carlo Rainaldi), which previously had its main entrance on Via di Santa Maria dell'Anima. The fašade was expanded to include parts of the bordering Pamphilii palace, gaining space for the two bell towers (each of which has a clock, as in St. Peter's, one for Roman time, the other for tempo ultramontano, European time).
Borromini lost this work before this was ended due to the death of the Pope Innocent X in 1655. The new Pope, Alexander VII, and Prince Camillo Pamphili called back Rainaldi, but this one didn't change very much and the church is mainly considered a notable expression of Borromini's concepts.
He was also called "Bissone", by the place in which he was born.
In the summer of 1667, Borromini, suffering from nervous disorders and depression), committed suicide after the completion of the Falconieri chapel (the main chapel) in San Giovanni dei Fiorentini, where he was buried.
Francesco Borromini was featured on the 100 Swiss Franc banknote current in the 1980s.