Nicholas V
"The influence of the holy see pervaded Christendom; and he exerted that influence in the search, not of benefices, but of books. From the ruins of the Byzantine libraries, from the darkest monasteries of Germany and Britain,
he collected the dusty manuscripts of the writers of antiquity; and wherever the original could not be removed, a faithful copy was transcribed and transmitted for his use.
The Vatican, the old repository for bulls and legends, for superstition and forgery, was daily replenished with more precious furniture; and such was the industry of Nicholas, that in a reign of eight years he formed a library of five thousand volumes."
Gibbon E.