Real Chiesa di San Lorenzo (Royal Church of Saint Lawrence), Turin

On the 10th of August 1557, the Feast of Saint Lawrence, the Hapsburg army, led by Emmanuel Philibert, Duke of Savoy, soundly defeated the French in the Battle of Saint-Quentin in France. Turin and Savoy were returned to Duke Emmanuel. He made the capital in Turin. He erected the Royal Church of Saint Lawrence in 1634.

Architect Guarino Guarini was a great fan and innovator of Baroque principles established by the Roman Architect Francesco Borromini. In the Church of Saint Lawrence, Guarini took the classical orders of column and entablature far beyond tradition.

The ground plan is a square. The square becomes an octagon at the level of the entablatures above the columns. It changes to a Greek cross at the level of the pendentives of the vaults. The base of the dome is circular, supported by eight ribs. The choir is elliptical. The high altar gets natural light from a hidden dome.

The dome is supported by eight intersecting arches reminiscent of the eight-pointed stars seen in mosques, with smaller windows decorating the areas between the arches. The lantern atop the dome is octagonal. As a result of the way the geometric characteristics interact with the reflection of light, the dome takes the shape of an ominous-looking face. People call it the "face of the devil."