Written by Jack GuySaskya Vandoorne, CNN

Two pieces of 16th-century armor have been returned to the Louvre museum in Paris almost 40 years after they were stolen.

The Renaissance-era helmet and body armor were made in Milan and encrusted in gold and silver, according to a statement from the Louvre on Thursday.

Baroness Salomon de Rothschild gave the armor to the French state in 1922. The pieces were on display in the Louvre when they were stolen overnight from May 31 to June 1, 1983, according to the statement.

“The circumstances of the theft of these pieces, little known to the general public, had remained a mystery,” said the museum.

The theft “deeply troubled” museum staff at the time, but the armor has now been recovered thanks to the work of investigators, according to the statement.

The armor will go on display in the Objets d’Art rooms in the Richelieu wing when the Louvre reopens. It closed to the public in October last year due to coronavirus lockdown restrictions.

The armor will go on display when the museum reopens.

The armor will go on display when the museum reopens. Credit: THOMAS SAMSON/AFPGetty Images

Such thefts are rare, but not unheard of.

One of the museum’s most famous works was stolen more than 100 years ago.

Before the 20th century, Leonardo da Vinci’s “Mona Lisa” wasn’t especially well-known outside art circles. But in 1911, a former employee of the Louvre pilfered the portrait and hid it for two years.

Public fascination with the theft helped cement the painting’s place in popular culture ever since.

The “Mona Lisa” is one of the star attractions at the world’s most-visited museum.

Last year, the Louvre lost more than 90 million euros ($109 million) in revenue and experienced a 72% drop in visitors due to disruption caused by the pandemic.

However, the museum is making the most of the closures by carrying out long-planned renovations.