Neptune and Mars in a square: Piazza del Popolo, Rome

Giuseppe Valadier’s intervention in Piazza del Popolo was initiated in 1794 when as a young architect he presented a project for the piazza’s redefinition to Pope Pius VI, and its effective militarisation by the erection of paired colonnaded barracks. With the French occupation of Rome in 1798 the architect redesigned his project as an urban garden space, associated with an adjacent public garden on the Pincian Hill, and introduced a cross axis centred on the obelisk placed there by Sixtus V. The elliptical garden space which was thus defined had its Roman origins in Bernini’s work at Piazza San Pietro but transformed for the neoclassical taste, and perhaps also the more recent example of Prato della Valle in Padua. A series of transformations would follow as the urban character of the space was emphasised and the civil engineering difficulties associated with the hill were resolved. In the centre of the piazza the obelisk was given a new base and surrounded by fountains featuring ‘egyptian’ lions. Low screen walls, ornamented with sphinxes formed the hemicycles with a fountain of Neptune towards the Tiber, and a fountain of Mars backed by a series of terraces, rostral columns and cascades against the Pincian Hill. The culminating feature was a three arched loggia supporting the final terrace where an elevated view towards the dome of Saint Peter’s was provided, an entirely appropriate change of directional emphasis once Pius VII returned to the city following the abdication of Napoleon in 1814. The papal administration was content to continue with Valadier’s project, with four substantial building elements created in an animated neoclassical language, a new flank wall to the church of Santa Maria del Popolo and a small barracks building framing the view of the Porta del Popolo, and a pair of commercial buildings framing Rainaldi’s twin baroque churches. The archaeological taste is evidenced by the piling up of motifs, including the statuary, the placing of another obelisk on the summit of the Pincian Hill and the decorative panels of militaria (similar to those on the Aventine) set within a romantic landscape which is designed to contrast dramatically with its urban context. The eclectic architectural language favoured by Piranesi had found an expression on a civic scale.