The architect Giacomo Barozzi da Vignola had been taken up by the papal family of the Farnese and worked with Michelangelo, who had deeply influenced his style.

Vignola has from 1564 carried on Michangelo's work at St. Peter's Basilica, and is to construct the two subordinate domes according to Michelangelo's plans.

He begins work on the church of Sant'Anna dei Palafrenieri in 1565: his oval-based plan, like his earlier design for the church of Sant’Andrea in Via Flaminia, represents a radical break with the Renaissance classical tradition.

Pope Pius IV, a lavish patron of scholars and artists, including the late Michelangelo, dies on December 9, 1565, having restored good relations between the papacy and the Habsburg dynasty under the guidance of his nephew Carlo Borromeo, archbishop of Milan.