The grisly true story behind one of the Louvre's most famous paintings

PARIS -- It's one of the most viewed works in the Louvre, yet few visitors know the horrifying real-life story behind "The Raft of the Medusa."

Theodore Gericault's desolate depiction of survivors washed out on a raft in the West African sea is admired for its ground-breaking use of Romantic swirls and chiaroscuro. But the painting is also a hanging testament to the horrific deaths of 133 sailors who perished. The event was one of history's most controversial naval tragedies, ending in shipwreck, political intrigue and cannibalism.

It all began in 1815 when King Louis XVIII sent a naval fleet, including the grand Medusa ship, to Senegal, to reclaim the land from the British. It was meant to be a trip of victory.

But the dramatic scene that unfolded was steeped, instead, in death: a vessel running aground off the coast of today's Mauritania, a bloody raft hurriedly constructed from the shipwreck, and desperate survivors going mad and eating each other.

Among those who drifted for 13 days on a 140 square-meter raft, only 15 survived to tell the harrowing tale.

Now, a French documentary is to explore for the first time the little-known story behind the masterpiece that's been hanging in the Louvre for nearly two centuries.

"Along with the Mona Lisa, it's one of the Louvre's most visited masterpieces. But do people know it's more than a legend? It really happened, and we're trying to shed light on why," producer Anne Fredon told The Associated Press.

With the help of a psychiatrist as well as author Steven Callahan, who in 1982 survived for 76 days adrift on the Atlantic Ocean in a liferaft, the 90-minute film tries to answer why the survivors degenerated so quickly into savagery.

The film, "The Raft of the Medusa's Real Story," will be broadcast on Arte in France and Germany in early 2015.