The church is dedicated to Cardinal San Carlo Borromeo, and its dome is the 3rd highest in Rome. The slogan of the Cardinal "Humilitas" (humility) is engraves in many sites within the church.
Notice the coat of arms of the Costaguti family in the chapel (three gilded eight-tipped stars over three gilded pointed lines, with blue background). It is the same you find everywhere in the palace.
Right: Tomb of the Cardinal Vincenzo Costaguti (1611-1660). He was appointed Cardinal very young, and he participated in the administration of the Catholic Church.
Like all the Costagutis, he was Marquis of Sant'Angelo, the old name of the "rione" or quarter which includes nowadays the Jewish quarter, the area around the Church Santa Maria in Campitelli and the ancient Theatre of Marcellus.
In 1655 he met the Catholic queen Christine of Sweden, which whom he had a fertile friendship, exchanging views about history, mathematics and music. He was renowned for his good-humoured character and for his great knowledge of music.
The other Cardinal, Giovanni Battista Costaguti, was responsible of the Papal Kingdom mint, and also of the food administration boar.