The arts patrons of today could learn something from Jean, the Duke of Berry. The third son of John II, the king of France from 1350 to 1364, Jean had a treasure chest of disposable income, which never hurts. But he had something more important than money—incredible taste. Around 1410, the duke commissioned an object that is a splendor of human history, recently described by the Financial Times as the “world’s most beautiful book.”

A statue of Jean, the Duke of Berry, by Jean de Cambrai, circa 1404.

In the horse country north of Paris, at the Château de Chantilly, the exhibition “The Very Rich Hours of the Duke of Berry” opens today. For this show, the book’s luminous pages have been removed from their bindings so that they can be viewed panoramically.

Created for a prayer book called Les Très Riches Heures, the illustrations are dazzling celebrations of earthly existence. They combine the glorious colors of early Italian Renaissance panel painting; the wealth of detail, meticulously articulated, that we admire in Flemish realism; and the elegance and refinement of French style.

January in Les Très Riches Heures.

Born in a splendid castle, the patron of this extraordinary artwork did everything with abandon. A bit of a wastrel, he married a 14-year-old girl with the lovely name of Joanna of Armagnac, who bore him seven children. (His Scottish mistress gave him yet another.) He had a private menagerie that included a leopard, a bear, a lion, and an ostrich. He spent so much money collecting lavish jewels and biblical objects (some of them dubious, such as the Virgin Mary’s engagement ring and nails from the Holy Cross) that he ended up leaving his heirs in enormous debt. Still, the duke had an exceptional eye for beauty, and the discernment he showed in commissioning new works resulted in masterpieces from the era’s greatest artists.

In this prayer book intended for private use, 121 illustrations relay stories, some rarely told, in the manner of a picture book. The page showing St. Jerome wearing a woman’s dress is one of the most unusual. Drawn with a rare mix of rhapsodic freedom and steely perfection, the small scene is full of things to see: the pink and green (really coral and jade) checkerboard floor; the heavenly blue of the gown, vault, and sky. Some passages are dense and others airy, and the forms relate with intense visual rhythm.

Profile Portrait of a Lady, by an anonymous Franco-Flemish artist, circa 1410–20, on view at the Château de Chantilly exhibition.

The basis of this unusual page is a story told in The Golden Legend, an assemblage of 153 hagiographies published in 1265 in Genoa. Jerome was a strict disciplinarian, notoriously dour, on whom his fellow monks played a joke. On the right, we see one of these rascals placing a blue dress next to Jerome’s bed while he is sleeping. When he wakes before dawn, the poor fellow, too drowsy to notice what he is doing, puts it on to go pray in the church, which is why, on the left, the monks in the pew are tittering. Bald and bearded, Jerome has not yet noticed that he has cross-dressed unwittingly.

Saint Jerome in a Woman’s Dress, a folio in Les Très Riches Heures.

If this was not the sort of scene you expected to find in a 15th-century manuscript, you will discover that it is just one of many surprises brought to life with ravishing artistry. Less than an hour from Paris, Chantilly in the summer is always a treat. The duke’s Les Très Riches Heures elevate the trip to an enchantment.

“The Very Rich Hours of the Duke of Berry” is on at the Château de Chantilly, in France, until October 5

Nicholas Fox Weber is the executive director of the Josef & Anni Albers Foundation and the author of 16 books, including the recent Mondrian: His Life, His Art, His Quest for the Absolute