With its chiaroscuro ceiling painted with ‘caissons’and rosettes, the Petitot Gallery takes its name from the French architect Ennemond Alexandre Petitot who designed the walnut wood bookshelves constructed by Drugman which cover the walls. The bookshelves have an architectural shape with sides and pilasters sculpted artistically with draped festoons of leaves and laurel hips surmounted by XVIII century amphora. A few years later under the direction of Ireneo Affò in 1791, the Library extended to the Gallery of the Incoronata which had once been the seat of the Farnese picture gallery.
The name comes from the painter Antonio Allegri known as il Correggio. The Incoronazione della Vergine is now housed in the National Gallery but was frescoed for the apse of the Church of San Giovanni Evangelista. The apse was destroyed in 1587 and the fresco was transported to the corridor with its masonry backing from which it was detached in 1937.
Only the sinopite remains still with the frame created by Girolamo Magnani. Thanks to the good offices of Angelo Pezzana and the munificence of Maria Luigia a series of works were undertaken in the first half of the XIX century in order to enhance the value of both the building and the heritage housed within its walls: the fitting out of the De Rossi room (1819-1821) with its ceiling frescoed by Giovanni Battista Borghesi, the construction of the new reading room (1830-1833) planned by the court architect Nicola Bettoli, as well as the decoration of the Librarian’s study, known in the XVIII century as the Room of the Fireplace and now the Dante Room.