La fabbrica del “corridore nuovo” nel Belvedere Vaticano: dal disegno bramantesco alle addizioni stratificate del secondo Settecento

The study deals with the systematic examination of the constructive history of the western corridor in the Belvedere complex in the Vatican from the pontificate of Pius IV (1559-1565) to that of Pius VI (1775-1799), analysing unpublished documentary and iconographic sources. However, it also and above all aims to identify the elements of permanence of Bramante’s project in the building. The survey is divided into three sections. The first one covers a period of about twenty years (1561-1585), a rather short, but decisive phase, not only as it is related to the construction of the west wing of the Belvedere Courtyard, but also because it is characterized by the earliest significant variations to its original design. The second part of the study starts with the construction of the Sistine Library, analysing diachronically the multiple consequences on the unity of the corridor, which between the end of the 16th and early 18th centuries is divided into various rooms, suitable for hosting the ever-increasing Vatican book collections. The third paragraph, inherent to the eighteenth-century phase, focuses on the new additions and changes made to the building to make it part of the Vatican Museums. In order to better document these transformations, this research comprehends, as well, some graphic reconstructions, made by the author and concerning the main construction phases of the corridor.