GRIMALDI, GIACOMO. – Priest and scholar, born in Bologna around 1560, died in Rome on 7 January 1623. He entered the service of the Vatican Basilica at a very young age as a supernumerary cleric (1581), later becoming sacristan, archivist, and beneficed cleric (1602).
He reorganized the Basilica’s Archives and, having been 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, as well as at the translation of the relics, he compiled detailed reports of these events. He also left unpublished writings in which he described monuments of Christian Rome that were being destroyed or moved: paintings, mosaics, statues, inscriptions, etc., accompanying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 on his instructions. He had a copy made of the apse mosaic of S. Pietro before it was demolished in 1592, drawing up a notarial document to record it (G. was also a public notary). His drawings of vanished ancient Christian monuments were used by later authors (the Bollandists, Ciampini, Bonanni, Muratori, Mai, Huelsen, etc.) and by modern art historians. Particular mention should 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 abundant information concerning the monuments, taken from the Archives of the Vatican Basilica and prefaced by G. himself, is illustrated with color reproductions of the monuments themselves. Original manuscripts are preserved in archives and libraries in various cities: Rome (Vatican Library, Archive of S. Pietro, Casanatense), Florence (National Library, Marucelliana), Milan (in addition to the Ambrosiana, the State Archives), Paris (National Library). The Archive of S. Pietro preserves an album containing color or pencil drawings collected by G., as indicated by the inscription «Veteris
Basilicae Vaticanae diagrammatum foliis num. 41 per Jacobum Grimaldi... collectorem volumen». Works of particular 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.