San Luigi dei Francesi was the firstborn of the first Marquis of Castiglione delle Stiviere. He was educated on military life but was only seven years old when he got close to Catholocism. He took a vow of “perpetual virginity” at the age of eight years old. He entered the Society of Jesus at 17, and the following year made the official renunciation of the title of Marquis.

He worked during the plague of Rome at the end of the 16th century and died at the age of 23. Sanctified in the 18th-century, his body is kept in Sant’Ignazio Church in Rome, the jaw is in the church of Rosolini in Sicily, and the skull was brought back to his hometown.