1. The museum started out as a fortress.

The Louvre began life in the late 12th century when Philip II (or Philip Augustus), the first person to be officially known as the King of France and one of medieval Europe’s most successful rulers, began construction on a defensive outpost near what was then the western border of Paris, along the bank of the River Seine. Designed to prevent invasions from the north, the arsenal included bastions at each corner, a surrounding moat and a massive, 98-foot-tall fortified tower, or keep, at its center. In the 14th century, with the city having spread far beyond its borders during Philip’s reign, a new series of defenses was constructed on the outskirts of Paris, and the fortress ceased to be used for defensive purposes. Today, visitors to the Louvre can view the remains of part of the fortress’ medieval masonry in the 13th century Salle Basse, or Lower Hall.

2. Philip’s fortress was razed to make way for a royal residence.

Charles V first modified the building’s original design in the 14th century, but the Hundred Years War derailed his more extensive plans for the Louvre. With successive monarchs opting to set up house elsewhere, the Louvre fell into disuse until 1527, when Francis I ordered the demolishment of the original structure in favor of a lavish new Renaissance-style compound. Indeed, Francis was an enlightened Renaissance ruler: An amateur poet and man of letters, he helped standardize the French language, he was the first European monarch in history to establish diplomatic relations with the Ottoman Empire and as a noted patron of the arts he cultivated a close relationship with Leonardo da Vinci, convincing the artist to move to France. The work Francis’ commissioned at the Louvre kicked off a century-long expansion; dozens of new wings and freestanding buildings were constructed at the site—many of them designed by the leading European architects of the day—which were eventually connected by a series of galleries and pavilions giving the building its unifying façade.

3. The buildings of the Louvre were once left abandoned and rotting.

Following the completion of the Palace of Versailles, the French court shifted its base away from Paris and the Louvre, leaving the building unfinished and in eventual disrepair. Those buildings that remained open eventually played host to a series of cultural groups that included painters, sculptors and writers as members. After more than a century, construction picked up once again, as a series of Bourbon kings lavished money on the site and the artistic contents within it—until the fall of the monarchy and the start of the French Revolution in 1789. With the deposed monarch and his family eventually imprisoned in the neighboring Tuileries Palace, the newly created National Assembly decreed that the Louvre be turned over to the government for the creation of a national museum open to the public. The Louvre first opened its doors on August 10, 1793, with an exhibit of more than 500 paintings and decorative arts, many of which had been confiscated from the royal family and French nobility.

4. The Mona Lisa hasn’t always been on display at the Louvre.

A number of da Vinci works would find their way into Francis I’s collection, including La Giaconda, one of the world’s most famous paintings. According to French folklore, Francis was even at da Vinci’s bedside when he died and following the artist’s death in 1519 , the king purchased the painting from an assistant. However, instead of gracing the walls of the Louvre, the painting spent centuries being shuttled among a series of royal palaces, spending time at Fontainebleau and Versailles. It was only after the fall of the monarchy and the establishment of the Louvre as a public museum that the Mona Lisa found a more permanent home. And there it has remained with a few notable exceptions: When Napoleon Bonaparte came to power, he had the painting hung on his bedroom wall. It was spirited away to safety in a secret location during the Franco-Prussian War and World War II. And in 1911 it was stolen right off the walls of the museum by an Italian criminal who claimed his motive was the painting’s repatriation to da Vinci’s native lands—for two years, visitors to the Louvre were greeted by a vacant spot on the wall where the painting had once been. After its return, the Mona Lisa wouldn’t leave the confines of the museum again for 50 years, until first lady Jacqueline Kennedy convinced French officials to allow the painting to tour museums in New York and Washington, D.C. for immensely popular events that became known as the first museum blockbuster exhibitions.

5. Napoleon Bonaparte temporarily renamed the museum after himself.

When Napoleon came to power he had the complex renamed in his honor, and soon the Musée Napoleon was overflowing with the artistic spoils of war as Bonaparte’s Grand Army swept across the continent. Among the cultural artifacts that made their way to Paris were hundreds of paintings and sculptures, including a set of antique bronze horses from the façade of St. Mark’s Basilica in Venice that became part of a triumphal arch outside the Louvre and another equine statue that had stood atop Berlin’s Brandenburg Gate. Napoleon had the statue, known as the “Quadriga,” packed up and sent to France for display in the Louvre, but it instead languished in storage until Napoleon’s fall in 1814, after which more than 5,000 pieces of art were returned to their rightful owners and Paris’ grandest museum got its current name.

6. The Louvre became a clearinghouse for artwork stolen by the Nazis during World War II.

One hundred and thirty years later, as another grand army swept across Europe (this time in the direction of France), conservators at the Louvre began to hastily prepare for the evacuation of tens of thousands of pieces of art. The first to go: The Mona Lisa, followed quickly by every valuable (or moveable) work. A caravan of more than three dozen trucks headed into the French countryside, shepherding the priceless works to safety in a series of private chateaus. After the German occupation of Paris, Nazi officials ordered the Louvre to reopen. It was an empty gesture, literally: The barren walls and ghostly corridors were now home only to those sculptures that had been too difficult to move (and even those that remained had been covered up by heavy burlap bags).

With no artwork to display, the Nazis decided to commandeer part of the museum as a clearinghouse to catalogue, package and ship art and personal items confiscated from wealthy French (primarily Jewish) families back to Germany. Known as the Louvre sequestration, it eventually took over six massive rooms in the museum, but it wasn’t the largest art theft operation in Paris during World War II. Under the command of Herman Goering, the nearby Jeu de Paume museum processed thousands of confiscated masterpieces. Many of them were earmarked for the personal collections of the Nazi high command, while those works deemed morally degenerate (including works by Picasso and Salvador Dalí) were sold to non-German collectors or eventually burned in a pubic bonfire at the Jeu de Paume in 1942. Thanks to an intrepid curator who served as a double agent during the plundering, many of the pieces that passed through the Jeu de Paume were eventually recovered. The Louvre, which had resisted working with the Nazis, was less successful in repatriating its lost artwork. More than 70 years after the Nazis marched into Paris, the museum continues to come under fire for its role in the greatest cultural theft in history and its reluctance to return contested artwork.