The chapel on the right, looking towards the high altar, since 1888 bears the title of the Immaculate Conception, represented on the panel painted that same year by Alessandro Franchi. The subject became a very frequent one in sacred art after the proclamation by Pope Pius IX in 1854 of the dogma attesting that Mary was free of original sin from the moment she was conceived. The Virgin, crowned with twelve stars, is framed by a mandorla of rays; this shape refers to Mary’s virginity. Her feet rest on a crescent moon, a detail that derives from the vision of the Woman, identified as the new Eve, described by Saint John in Revelations. Moreover, the Virgin steps on the serpent on top of the globe of the world, symbolizing the victory over original sin. This iconography comes from a passage in Genesis (3:15) and means that Mary is the Mother of Him who, by sacrificing Himself, would defeat Satan, freeing mankind from enslavement to evil. At Mary’s sides are Saint Michael the Archangel holding the scales, and Saint Clement the Pope, who were the titular saints of the two parishes in Siena encompassed by the church of the Servites.

The next chapel moving to the right has a complex history; over the centuries its name has changed several times, according to the works that were placed there. The Petroni family, its first patrons, commissioned the fourteenth-century frescoes, of . . .