[4] Its founder, in whose honor the library is still named the Biblioteca Angelica, was an erudite scholar and keen collector of rare editions.

The question of finding suitable premises for housing the library was in all likelihood the cause for the delay in carrying Rocca's plan into effect.

In 1661 the German humanist Lucas Holstenius, caretaker of the Vatican Library, bequeathed to the Biblioteca Angelica his precious collection of about 3,000 volumes.

The hall, known as the Vanvitelli's “vase” because of its shape, is characterized by a rectangular plan, barrel vault and a precious wooden shelving by Nicola Fagioli.

They come chiefly from the ancient Augustinian convent of Santa Maria del Popolo, from the Rocca, Holstenius and Passionei funds and from diverse inheritances previous to 1870.

The library owns more than 1,100 incunabula, including an edition of the first book printed in Italy: the De Oratore by Cicero, produced in 1465 at Subiaco by Arnold Pannartz and Konrad Sweynheim, German proto-printers.

Other particularly valuable incunabula owned by the Angelica are the following: the Divinarum istitutionum by Lactantius of 1468; the Epistolae by St. Jerome of 1468; the Commentaria in Evangelistas of 1470; the Storia naturale [Natural History] by Pliny of 1470; a Divina Commedia printed in Florence in 1481 with Landino's commentary and engravings made to Botticelli's design.

Included in the works of the sixteenth Century, an edition of Orlando Furioso printed at Ferrara in 1521 and a copy of the Vulgate Bible of 1571 with the autograph corrections of Sixtus V are quite noteworthy.

[10] Since 1940 the Angelica has also become the seat of the Pontifical Academy of Arcadia which gave it on deposit the historical archives and the library with its wealth of 10,000 volumes comprising hundreds of books, pamphlets, academic writings, periodicals, unique issues, authographs that are a faithful evidence of the background and the development of the life of the academy whose first seeds date back to the meetings held in Rome in the palace of Queen Christina of Sweden.