In 1577 Emanuele Filiberto, then Duke of Savoy, was fighting, along with his cousin, Philip II, against the French.
On the eve of the Battle of San Quentin – on San Lorenzo Day, August 10 - vowed to erect, in case of victory, a church in honour of the Saint.

In Madrid, Philip II ordered the construction of the abbey built in the shape of a grid , an instrument of the martyrdom of the saint. In 1562 on his return to Turin Emanuele Filiberto, unable to immediately erect the church, fortified the city and restored the ducal chapel "Santa Maria della Natività" dedicated to San Lorenzo.
The duke died without having built a real church that was consecrated only in 1680 by Guarino Guarini, a seventeenth-century genius of architecture in Turin.

This church has a simple facade, uniformed to nearby buildings. In place of the ancient church of Santa Maria there is the Oratory just before the Church. The interior is octagonal with convex sides, topped by a dome with a lantern light.

Behind the sides there are four chapels diagonally concave. The structure, reduced to essential elements, captures light through large windows and gives the building a strong vertical impetus. The shell of the dome is supported by columns of serliane; it is illuminated by eight elliptical windows and crossed by a system of ribs forming an eight-pointed star at its centre and it is a regular octagon.
The number eight , infact, the symbol of perfection and infinity of Christian esotericism.