Several previously unpublished contracts demonstrating the involvement of Alberto da Piacenza in works carried out in the cloister of San Pietro in Vincoli in Rome constitute a small addition to the laborious reconstruction of the biography of this builder who was active in a number of papal projects and construction sites in the early sixteenth century. Although these documents only partially fill the documentary gaps that inhibit an accurate dating of the various wings of the Lateran Canons’ complex, thanks to the information amassed up to now in the scholarship on Alberto da Piacenza, it is possible to specify his role as architector. This will facilitate the avoidance of simplistic attributive hypotheses and errors when confronting difficult issues such the role and “friendships” between Bramante and the many Lombards then present in Rome.