The first chapel on the right is dedicated to Saint Barbara (the patron saint of gunners). The chapel, completely renovated in 1740, was erected in 1594 by Cardinal Pietro Aldobrandini, nephew of PopeClement VIII, and by his lieutenant Americo Capponi thanks to the offers collected by the soldiers of Castel Sant'Angelo gathered in the brotherhood known as the bombardiers. Among the privileges of this confraternity was to free every year two convicts, one on September 29, the feast of St. Michael the Archangel and the other on December 4, the feast of Santa Barbara.