The families Boncompagni and Ludovisi were joined in with the marriage of Duke Gregorio I Boncompagni and princess of Piombino, Olimpia Ippolita Ludovisi in 1681 and their archives and libraries were combined. These collections predate the union, however, with sections of the archive dating to the 14th C. Both families originate in Bologna, the Boncompagni moving to Rome in the late 16th C with Ugo rising through the Curia to become Pope Gregory XIII in 1572. The Ludovisi moved to Rome in the 17th C, Alessandro leaving again in 1612 to become Archbishop of Bologna, and returning in 1621 as Pope Gregory XV. After negotiations, Prince Francesco Bongompagni Ludovisi donated the archives and libraries to the Vatican in August 1947, though the actual physcial transit lasted until 1952. The archives and library were seperated to the BAV and the Archivo Apostoli, though the ctiteria are unclear.

Currently 36 manuscripts have been digitized out of the 911 manuscripts in the collection. These are spread across 919 shelfmarks, the disposition of the remaining 8 manuscripts is unknown.

Sources

1. Biblioteca apostolica vaticana. (2011). Guida ai fondi manoscritti, numismatici, a stampa della Biblioteca vaticana. Biblioteca apostolica vaticana. pp. 352-354
2. http://www.archivioapostolicovaticano.va/content/aav/en/attivita/ricerca-e-conservazione/progetti/inventariazione/archivio-boncompagni-ludovisi.html