Alle origini dell’Album del Grimaldi (Arch. Cap. S. Pietro A. 64ter). Il liber picturarum di Domenico Tasselli e altri disegni del vecchio e del nuovo San Pietro

In conjunction with the plan of Tiberio Alfarano (1590), the designs in the codex Arch. Cap. S. Pietro A. 64ter are the most important source for drawings of the ancient Vatican basilica. This large-format Album is associated with the cleric Giacomo Grimaldi (1568-1623), who placed autograph notes on the folia of the two main series of drawings. Previously known as libri picturarum, the two collections were achieved by Domenico Tasselli da Lugo (1578-1630) and other professional illustra-tors a short time before the Constantinian basilica was demol-ished. Starting from the reconstruction of the dramatic histori-cal circumstances for a documentary enterprise that was with-out precedent, this study examines the Album’s images in an innovative way, making use of the opportunities presented by the digitalization of the manuscript. By means of the recon-struction of the ancient foliation of the paper together with an evaluation of an earlier parchment illustration that in 1592 documented the apse mosaic of St. Peter’s before its destruc-tion, this contribution sheds new light on the structure of the “watercolor book” by Domenico Tasselli (1606), on the origi-nal nature of the second set of drawings (1609), and on the important role that Giacomo Grimaldi played in a documen-tary project “in pictura et scriptura” that was quite modern in its form.