Before the invention of printing in the mid-fifteenth century, books were precious, one-of-a-kind objects, hand-made and decorated with miniature paintings and decorative marginalia. The Très Riches Heures was created by a team of brilliantly talented artist-brothers for the fabulously wealthy bibliophile and collector Jean, Duke of Burgundy.  Considered one of the great treasures of art history, this miracle of manuscript illumination is stored today in a bomb-proof bunker, where it cannot be damaged or destroyed (or even seen).