This is the largest church in Turin, 69 metres long by 37 metres wide. The building was begun in the second half of the 17th century to the plans of Antonio Bettino but the collapse of the dome in 1714 necessitated reconstruction and this was entrusted to Filippo Juvarra. However, the building was actually finished after 1823 by the architect Giuseppe Maria Talucchi and the frontispiece over the door of the façade was finally completed by Ernesto Camusso in 1891. Inside the church there are works of great worth, for example the main Baroque altar, the organ loft and the font in the sacristy. Adjacent to the church is the Oratorio built by Tavigliano to designs attributed to Filippo Juvarra.