The Nativity of Mary or Chapel of the King
The chapel was commissioned by Vincenzo I, Duke of Mantua and Monferrato, whose coat of arms was later replaced by the effigy of the House of Savoy. The interior scene shows an episode of daily domestic life. Saint Anne is in bed, just after giving birth, while a maidservant is giving her an egg. Three other maidservants are taking care of Mary's first bath. Four Prophets are housed in niches: David, Isaiah, Jeremiah and Ezekiel. They are attributed to Melchiorre d'Enrico the Elder and Michele Prestinari and his son, as documented by the payments made around 1593. The frescoes on the side walls were renewed in 1637, thanks to Giovanni Antonio Veglia from Asti. They tell the stories of the Birth of Acsa, daughter of Caleb, and the Birth of Mikal, daughter of King Saul, relating the Virgin Mary to the biblical heroines. In 1715, when the Savoys took over from the Gonzagas, the chapel was adapted to the new situation: Vittorio Amedeo II ordered the replacement of the oldest staircase, with the current baroque one. In 1859, Vittorio Emanuele commissioned the marble altar, the internal flight of steps, and some remaking of the frescoes by Martini di Robella.