"The vast body of over 100 paintings and drawings by Raphael assembled for this occasion constitutes the largest ever seen all together in the world," the museum said in a statement.
Some 200 works in total will be on display, including paintings and drawings by other artists that will be shown alongside Raphael's for comparative purposes.
The show will be "an appropriate tribute to celebrate the rank and the fame of such a universal artist in occasion of the 500th anniversary of its death," Culture Minister Dario Franceschini said.
Florence's Uffizi Gallery, home to the world's largest permanent Raphael collection, will be loaning more than 40 of his artworks and is co-organizing the exhibition.
Other pieces are expected to come from the Louvre, which in September agreed to send to Rome five Raphael works in return for the Italian loan of seven Leonardo da Vinci pieces.
The Paris museum is currently hosting another 500th anniversary exhibition on Leonardo, including his famous "Vitruvian Man" drawing, normally held in Venice's Galleria dell'Accademia museum.
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