The (BnF; ) is the National Library of France, located in Paris. It is the national repository of all that is published in France. 

The National Library of France traces its origin to the royal library founded at the Louvre Palace by Charles V in 1368. Charles had received a collection of manuscripts from his predecessor, John II, and transferred them to the Louvre from the Palais de la Cité. The first librarian of record was Claude Mallet, the king's valet de chambre, who made a sort of catalogue, "Inventoire des Livres du Roy nostre Seigneur estans au Chastel du Louvre". Jean Blanchet made another list in 1380 and Jean de Bégue one in 1411 and another in 1424. Charles V was a patron of learning and encouraged the making and collection of books. It is known that he employed Nicholas Oresme, Raoul de Presle and others to transcribe ancient texts. At the death of Charles VI, this first collection was unilaterally bought by the English regent of France, the Duke of Bedford, who transferred it to England in 1424. It was apparently dispersed at his death in 1435. 

Charles VII did little to repair the loss of these books, but the invention of printing resulted in the starting of another collection in the Louvre inherited by Louis XI in 1461. Charles VIII seized a part of the collection of the kings of Aragon. Louis XII, who had inherited the library at Blois, incorporated the latter into the "Bibliothèque du Roi" and further enriched it with the Gruthuyse collection and with plunder from Milan. Francis I transferred the collection in 1534 to Fontainebleau and merged it with his private library. During his reign, fine bindings became the craze and many of the books added by him and Henry II are masterpieces of the binder's art.
Was he originally hired for that job?
The first librarian of record was Claude Mallet, the king's valet de chambre