Italian architect, part of a family of artists. The father of Carlo Rainaldi, he began his career as a draughtsman in the studio of Domenico Fontana, and early works included the construction of the catafalques for Cardinal Alessandro Farnese in Il Gesù (1589) and Pope Sixtus V in St Peter's (1590). He produced a scheme for the completion of St Peter's for the competition of 1607, which was won by Carlo Maderno, although Girolamo was under the patronage of Cardinal Odoardo Farnese. Girolamo was active on several projects outside Rome, largely unfinished. His most successful undertaking was the Carmelite church of San Silvestro (1620; now Santa Teresa), Caprarola. Its longitudinal plan is countered by a broad transverse axis created by chapels set in the centre of the long walls. The picturesque façade is embellished with Serlian motifs. Girolamo became the architect of the Popolo Romano in 1612 and his engineering projects included the placement and upkeep of bridges on the River Tiber. He served as President of the Accademia di San Luca in 1640 and as Regent for the Congregazione dei Virtuosi al Pantheon in 1640 and 1650. His appointment as Papal Architect in 1644 led to a commission from Innocent X for the design of the Palazzo Pamphilj (1645-50) in the Piazza Navona. In 1652, in collaboration with his son Carlo Rainaldi, he began work on Sant'Agnese in Agone, the family church of the Pamphilj in the Piazza Navona). Girolamo also worked on altars for the Borghese Chapel in Santa Maria Maggiore. His other projects in Rome included the Colonna Chapel in San Giovanni in Laterano, an altar in Santa Maria Maggiore and the tomb of Cardinal Sfondrati (d. 1618) in the portico of Santa Cecilia in Trastevere. In 1616 he expanded the upper gardens of Villa Farnese in Caprarola for Cardinal Odoardo Farnese. In 1617-19 he laid out the formal gardens south of the casino of the Villa Borghese, Rome, and added an open-air theatre to the east. //