Yesterday, on August 21 at 7:30am, a man of average stature moving at a deliberate and measured pace exited the main entrance of a well-known Parisian building. Pinched under his arm was an inch-and-half-thick panel of poplar wood wrapped unceremoniously in a white smock. He crossed the connecting courtyard and made his way to the street with quickening steps, his pulse mounting with excitement and disbelief. Could it really have been that easy?

He traced a carefully chosen path toward the bus station as his hand nonchalantly released a small object into a nearby ditch. The street was eerily quiet, as was most of Paris this time of year; any gentlemen who had remained in the city were shuffling briskly toward offices or away from the previous night’s romantic endeavors. Had these hurried pedestrians bothered to track the movements of the Italian immigrant with a white bundle under his arm, they would have recognized the object leaving his hand as it reflected its contours in the hazy morning sun, revealing itself to be a most curious and incongruous item — an antique doorknob.

The man mounted a bus, though soon realizing that in his nervous haste he had taken the wrong one, took a taxi and headed northeast to 5, rue de l’Hôpital Saint-Louis.

He entered his apartment, unraveled the white cloth, and placed the wooden panel on the table.

A mile and a half away, the building he had just left was still sleepily setting its gears in motion. Following its usual schedule the institution was closed to the public for the day and admitted only authorized personnel. At 8:35am Monsieur Picquet was making his rounds as the museum’s maintenance director through the gallery of the Salon Carré, on the walls of which hung the most esteemed collection of paintings in Europe. One of them — in fact one of the most valuable – wasn’t there.

Picquet wasn’t alarmed. The piece had been removed by a curator or a museum photographer, surely. That’s why the area was closed to the public in the first place, so that the necessary handling of its objects could be executed without exciting the dismay or consternation of paying customers. The director moved on.

This portion of the gallery wall remained bare the entire day, as countless workers dressed in traditional white smocks passed unfazed and unconcerned by the masterpiece’s absence. It wasn’t until the following morning, when the museum opened its doors to the usual early crowd of amateur painters, that the shocking truth was brought to light.

Louis Béroud was one of these early risers and had been spending his days in the Louvre fueled by a passion for great portraiture. Before the tourist crowds arrived to engorge the museum’s public spaces it was possible for a lover of the Old Masters to set up an easel and pay respects by painting his own copy of a favorite work, with the original at arm’s length serving as the ultimate model.

This morning Béroud was disappointed however, as the enchanting lady he had been spending his mornings with had not shown up for the appointment. He inquired as to her whereabouts, forcing a guard to visit the museum photographer who in turn claimed he had seen nothing of the painting recently. Panic steadily spread throughout the building as it became clear that one of the Louvre’s prized possessions had been whisked away from under their noses.

Someone had stolen La Joconde, known also by her English nickname: the Mona Lisa.

It was thus that the most momentous art heist in history began to unfurl its unlikely events, beginning with the diabolically simple theft of Leonardo da Vinci’s master work, on the morning of August 21, 1911 — 101 years ago yesterday.

A nation-wide investigation was immediately launched. The French police closed all borders and checked every package moving across it. Small panels were  monitored in particular, as the famous portrait wasn’t painted on canvas but directly on a slab of wood. The museum was shut down and combed over for evidence, revealing the painting’s display case which had been discarded by the thief in a nearby stairwell. A very clear left-hand thumbprint had been left on its pane of glass; however at the time the police kept records of only right-hand fingerprints, which rendered the clue utterly useless.

The news story spread across the world. Countless Parisian suspects were brought in to be questioned. Anyone with ties to art-related misdemeanors was scrutinized, and even a young Pablo Picasso was temporarily held on suspicion. His earlier involvement with the alleged purchase of artifacts stolen from the Louvre was enough to put him in the hot seat, but not enough to link him to this particular crime.

What the police could have never imagined is that the prize was only a mile and a half away, practically at the museum’s doorstep. The Mona Lisa would rest secretly within the small recesses of the thief’s Paris apartment, quietly hidden under the false bottom of a wooden chest beneath his bed. It would remain there for over two years.

The story would take other twists and turns along the way, with facts emerging slowly. Police would learn that the culprit, Italian-born Vincenzo Peruggia, had done some work for the Louvre previously, helping to construct the very case the Mona Lisa was set in. He had either hidden himself the night before in a closet for easy access once the museum reopened, or had simply entered the next day through the building’s main entrance.

On the morning in question he donned a white worker’s smock, lifted the painting’s heavy case off the wall, and brought it to the staircase to liberate the small 21 x 30 inch panel from its bulky shell. The door to the exit was unexpectedly locked, forcing Peruggia to remove the doorknob which he would later discard outside. He then passed unnoticed across a courtyard and a museum guard post, disappearing into the city’s web of avenues and alleyways.

He patiently kept his secret and avoided suspicion for 28 months, until 1913 when he showed the painting to a gallery owner in Florence and claimed it was he who had taken the missing treasure. This led to his arrest and subsequent trial, after which he received the whopping sentence of seven months in prison. Even more shocking, his incarceration leading up to the trial had already exceeded this by a few days, so the authorities released him immediately.

Peruggia’s real intentions for stealing the Mona Lisa were never concretely determined. He chose to paint himself as an Italian patriot, risking life and limb to return Leonardo’s masterpiece to the country where it belonged. His compatriots viewed him as a hero; women would send him cakes and flowers as a thank you for his efforts. But in the end he was likely after a payday for himself and his family, as is evident during his conversations in Florence before his arrest. Later a fantastical theory emerged that the theft had been part of a grander scheme, masterminded by an art dealer who planned to sell forgeries of the stolen piece to gullible American collectors who would pay top dollar for what they thought was delicious stolen property. The legend says that one day these forgeries will resurface to corroborate the story, but to this day none of them have.

Wherever the truth may fall, the event has all but faded away into the dark halls of history, with very few Louvre visitors aware of such an incredible wrinkle in this lady’s already enigmatic past. And ironically the story we never hear about is the very reason the painting now garners six million visitors each year – its disappearance placed it in the global consciousness and elevated its notoriety above all other works. At the time of the theft it was far from being a world famous object, obscure enough that the Washington Post didn’t even use the correct image for their breaking story:

Even if it wasn’t well-known at the time, clearly Leonardo’s portrait was about to benefit from this blast of early 20^th century hype. Without it, we would still respect the painting’s beauty but probably not much more than any other Renaissance triumph. The crowds in the museum right now might just as easily be surrounding a Titian or a Michelangelo were it not for Peruggia’s bold move a century ago.

Today the Mona Lisa hangs out of reach, behind bulletproof glass and sealed in a climate-controlled environment with humidity maintained at 50%. The case’s internal temperature is kept between 64 and 70 degrees Fahrenheit at all times to protect its wood from deteriorating, and the back is periodically treated with chemicals to prevent insect infestation. Every hairline crack on its varnished surface has been meticulously documented for future authentication, if need be. Perhaps it’s a bit of over-pampering; perhaps it’s overcompensation for a lack of surveillance in years past. Perhaps it’s simply a manifestation of the truth that you don’t know what you’ve got till it’s gone.