Notre-Dame’s Treasures, Untouched by the Fire, On View in Paris

The newly renovated Notre-Dame isn’t scheduled to reopen to the public until Dec. 8, 2024, but some of the cathedral’s oldest treasures — survivors of revolutions, regime change and disasters — are now on display at the Louvre.

And, although they had been inside the cathedral for centuries, the existence of some of these pieces came as a total surprise, even to experts.

More than 120 objects, ranging from medieval illuminated manuscripts and a 12th-century bishop’s gold ring to ornately embroidered vestments and multiple reliquaries — which once housed what was said to be Jesus’s crown of thorns and fragments of his cross — are featured in “The Treasury of Notre-Dame Cathedral, from Its Origins to Viollet-le-Duc” (through Jan. 29).

The title refers to Eugène Viollet-le-Duc, the celebrated French architect who restored the building in the mid-19th century, adding its spire (which collapsed in the 2019 fire), its famous gargoyles and other features. But he also designed furniture and objects used for ritual and worship, some of which are highlights of the show: an imposing gold vessel, dating to 1867, that was used during devotional ceremonies to display a consecrated host, and an intricately enameled gold dove that served as a receptacle for holy oils.

While Notre-Dame’s sacristy — a separate space, off the choir, which held the cathedral’s treasury — was not touched by the blaze that tore through the building on April 15, 2019, the destruction of the site and its security system meant that all the cathedral’s treasures had to be removed immediately, said Anne Dion-Tenenbaum, a co-curator of the exhibition. Most pieces are now being stored in the Louvre’s Department of Decorative Arts, where she is the deputy director.

“It gave us an opportunity to really study these objects, whose spiritual dimension makes them very striking,” Ms. Dion-Tenenbaum said in an interview. Over time, she and her fellow curators uncovered a few surprises in the treasury, which led them to look in other repositories around Paris and the rest of the country to unravel the mysteries of what was in the treasury, what wasn’t and what it all meant.

One rare document they turned up contained the first known reference to the treasury: In a will dating to the sixth century and written on papyrus, during the first Frankish dynasty of ancient Gaul, a Merovingian noblewoman named Ermentrude left a silver plate worth 60 gold coins to Notre-Dame. And a richly colored prayer book illustration, from around the 15th century, depicted the moment in the early 12th century when what was said to be a fragment of Jesus’s cross arrived at Notre-Dame.

The grand cathedral’s repositories also yielded highly embellished garments from the 19th century, like a cope, or long cloak, in gold cloth embroidered with lilies, peonies and oak branches, made about 200 years ago for King Charles X of France by silk manufacturers in Lyon. An elaborate, all-but forgotten ecclesiastical cape worn by an Italian cleric at Napoleon’s coronation in 1804 resurfaced, too. Though it is depicted in a monumental painting by Jacques-Louis David that is on display at the Louvre, the cape had never been identified as being worn at the event, and so was stored, anonymously, for more than two centuries. The “Treasury of Notre-Dame” exhibition is its first public showing.

Many objects in the exhibition are not known by Parisians, Ms. Dion-Tenenbaum said, because, in the past, the treasury primarily was visited by tourists. But once the cathedral reopens, she hopes that the French, too, will discover the synergies between Viollet-le-Duc’s renovation of the building and the objects it has held.

“What characterizes this treasure is that it’s a very homogeneous example of the 19th century,” she said. “That the place, its vitrines and its contents are all the work of a single architect gives it a harmony that is unique in the world.”