GRIMALDI, GIACOMO. - Priest, scholar, b. in Bologna ca. 1560, d. in Rome on 7 January 1623. He entered the service of the Vatican Basilica at a very young age, as a supernumerary cleric (1581), then sacristan, archivist, benefited cleric (1602).
He reorganized the Archive of the Basilica, and, being present at the demolition of the last part of the old Basilica for the extension of the new one in the form of a Latin cross and at the translation of the relics, he compiled accurate accounts of these. He also left unpublished writings, in which he described monuments of Christian Rome that were being destroyed or moved: paintings, mosaics, statues, inscriptions, etc., accompanying the text with numerous drawings executed by himself or, according to some, by others following his instructions. He had a copy made of the apse mosaic of St. Peter's, before it was demolished in 1592, drawing up a notarial record of it (G. was also a public notary). His drawings of ancient Christian monuments that have disappeared were used by later authors (Bollandists, Ciampini, Bonanni, Muratori, Mai, Huelsen, etc.) and by modern art historians. Particular mention must be made of the seven large-format volumes, prepared between 1617 and 1621, which G. sent to Milan to Cardinal Federico Borromeo, his patron. The copious information concerning the monuments, drawn from the Archive of the Vatican Basilica, with prefaces by G. himself, is illustrated with color reproductions of the monuments themselves. Original manuscripts are preserved in archives and libraries of various cities: Rome (Vatican Library, Archive of St. Peter's, Casanatense), Florence (National Library, Marucelliana), Milan (besides the Ambrosiana, the State Archive), Paris (National Library). In the Archive of St. Peter's there is preserved an album, containing drawings in color or pencil, collected by G., as is indicated by the inscription «Veteris
Basilicae Vaticanae diagrammatum foliis num. 41 per Jacobum Grimaldi... collectorem volumen». Works: of special note: Diarium anni 1600 (concerning the Jubilee of that year) in cod. Vat. Barb. lat. 2210; Istrumenta authentica translationum sanctorum corporum et sacrarum reliquiorum e veteri in novum templum S. Petri sub Paulo V P. M. cum multis memoriis, epitaphis et inscriptionibus basilicae eiusdem fideliter accurateque scripta et publicata a. D. 1621, in cod. Vat. Barb. lat. 2732-33.