Pierluigi Galletti (Rome, 1722-1790) was born to Costantino Galletti in Rome, where his father had moved from Messina to join the Papal army. Baptized Paolo Filippo, he took the name Pier Luigi when he entered the Benedictine order in 17461. He was ordained Bishop of Cyrene, a Titular See in name only, in 1778 and died in Rome in 1790, at the age of 68. So far 296 volumes of Galletti's work have been digitized by the Vatican.
While a monk at St. Paul outside the Walls he began copying the inscriptions found on the basilican floors, the other buildings of the monastery, and the surrounding vinyards. This was the start of a lifetime of work copying inscriptions found in churches throughout central and northern Italy. He also copied and indexed the Register of Farfa, a Monastery in Lazio, and did similar indexing on the Roman Necrology, as well as collecting the history of the Roman Curia and several of the Orders of the church. As an archaeologist he identified the ancient locations of Gabi and Capena.
Since many of his works deal with the history of Rome, they are catalogued in
Forcella, V. (1879). Catalogo dei manoscritti riguardanti la storia di Roma che si conservano nella Biblioteca Vaticana. Fratelli Bocca.
Notes
https://www.catholic-hierarchy.org/bishop/bgallpl.html.