Italian architect (Rome 1762 – 1839). Luigi's son, he was still very young when, designated as the architect of the Sacri Palazzi (1781), he had to attend to very important works of restoration (arrangement of the Dome of Spoleto) and reconstruction (Dome of Urbino), that represented for him a fundamental experience, contributing to form in him that sensitivity for architectonical and urbanization problems that make of him the first architect in a modern sense that Italy ever had. The utmost document of his capacity of facing in an organic way the problems that already at his times came along with a city's building development, was the arrangement of Piazza del Popolo in Rome (iter 7), for which he favored two projects (1793; 1810), both unrealized, until Pio VII's return to Rome (1814) did not allow him to begin the works (1816) and complete them. Convinced of the necessity of valuing the green zone of the inhabited areas and led by his town-planner sensitivity to project large connection arteries, Valadier was able to very cleverly adopt the ellipsoid scheme proposed for the piazza by the Parisian architect Berthaut, simultaneously satisfying the demand, deeply felt by him, of linking the churches of Rainaldi and C. Fontana with the monumental access he had projected for Pincio. While he was completing Piazza del Popolo, Valadier was carrying on a huge architectural work (in Rome: Palazzo della Calcografia, churches of S. Pantaleo, Valle theater, Valadier 's countryhouse in Pincio, Lezzani houses in piazza Barberini and in the Corso, etc.) always keeping to neoclassical schemes mitigated by French or Venetian elements, and unfolded a very important activity of restoration of ancient monuments (Ponte Milvio, 1805; Titus' Arch, 1819), that makes of him the initiator of restoration as it's understood nowadays. His work as a essayist and writer was also very large, resulting in the publishing of five volumes of a Manual of practical architecture (1828-39) (his son Luigi Maria (born 1791) collaborated with his father and drew the last of his graphical works).