The church was begun by Mascherino (1598). Girolamo Fontana II's main work is the remodelling and completion of the façade of S Pietro in Frascati (commissioned 1696). He designed a two-tiered front articulated by heavy columns in both storeys. The upper level is surmounted by a huge segmental pediment, a conscious allusion to Giacomo della Porta's nearby Villa Aldobrandini (1598-1603). Girolamo skilfully refashioned the existing bell-tower on the right-hand side and matched it with a similar one on the other side to create strong vertical accents. The façade (apart from the sculptural decoration) was essentially complete by 1700. Its somewhat conventional effect is due to the architect's desire to integrate his scheme with the existing structure in a style compatible with the local idiom.