The nineteenth century has been crucial for the development of architectural restoration. Actually, in the first three decades of the century significant events took place in the Roman ambit. These experiences have already been extensively investigated by scholars. Luigi Poletti from Modena (1792-1869) was one of the leading figures in this environment: as an architect, an engineer and an academic, he was pupil of some of the most influential masters of his time, such as Antonio Canova and Raffaele Stern, and operated in the greatest architectural enterprises of the State of the Church. A very productive professional, mainly known for his contribution to the reconstruction of the basilica of San Paolo fuori le mura, he was in charge of many other interventions on buildings and ruins in Rome and in its hinterland as well. Among them, it is worth mentioning the reconstructions of the basilica of Santa Maria degli Angeli in Assisi and of San Venanzio in Camerino, as well as the restorations of the church of Consolazione in Todi and of the Tempio Malatestiano in Rimini.Some more initiatives remained at the stage of projects, such as the restoration of the cathedral of San Ciriaco in Ancona ant the reconstructions of Ponte Rotto and Porta San Pancrazio in Rome.In addition, it is worth mentioning Poletti's academic experiences and his activity in the Pontifical administration (Commissione Ausiliaria di Antichita e Belle Arti). This volume offers a monographic analysis of Poletti's approach to architectural restoration and, at the same time, provides a broader overview of the theoretical and operative context of that period, carried out through this significant case study.The relevant research highly benefited from the information gleaned from the architect' s private archive, still preserved in Modena. This allowed the author to study with deep accuracy and plenty of information Poletti's activity as a whole in all of its complexity, including the wider cultural framework as well as his personal contributions.