Della Valle masterpiece is his Annunciation relief (1750) for the church of
Sant'Ignazio in Rome, a much more restrained and flatter relief than that of
Bernardino Cametti's elaborate 1729 treatment of the same theme now at the
Basilica of Superga. This reflected a
Neoclassical influence beginning to affect Late Baroque Roman sculpture, moving away from the theatrical to a more sober elocution of the subject. Another contrast can be found in
Pierre Legros the Younger's handling of the relief depicting St Aloysious Gonzaga in Glory (1698), which stands across from Della Valle's Annunciation in Sant'Ignazio.[1]
He also completed the statue of Temperance (1734) in the Corsini Chapel at
San Giovanni in Laterano. The statue recalls
Francois Duquesnoy's pioneering early baroque, yet soberly classic,
Santa Susanna. In this chapel, della Valle, working with Maini, shows the influence of the Florentine
Massimiliano Soldani Benzi. In style, della Valle was allied to the rising group of French sculptors in Rome including
Michelangelo Slodtz.