ON JULY 2, 1816, the French navy frigate Meduse ran aground 100 miles off the coast of Mauretania in Africa due to the navigational incompetence of its master Viscount Hugues Duroy de Chaumareys, a protege of the French foreign minister.

Some 147 people — for whom there was no room in the lifeboats — were put on an improvised raft to be towed. But, in a callous act of wilful and criminal negligence of duty, it was cut adrift on the orders of de Chaumareys.

Only 15 were to survive the two-week ordeal at sea before they were rescued. Immediately, stories of dehydration, starvation, brutality, murder and cannibalism emerged, when a report by the ship’s surgeon, Henri Savigny, was leaked to the newspaper Journal des Debats and published on September 13 1816.

France was in shock and the news travelled the world.

Theodore Gericault painted The Raft of the Medusa in 1819 as an emotive and intensely political response to a tragedy that shook post-Napoleonic France. It was an indictment of the first government of restoration, which brought the Bourbons back to the throne.

Gericault’s approach was that of investigative journalist. He conducted a minute forensic reconstruction of what was de facto a crime scene, including extensive interviews with the victims. The project took him 18 months, eight of which were spent on the painting.

At the 1819 Paris Salon exhibition, Gericault’s unnerving painting mercilessly assaulted prevailing aesthetic sensibilities and stunned  the critical fraternity, most of whom reacted with knee-jerk hostility.

Gericault's vast canvas — some 35 square metres — heralded the arrival of Romanticism. It emanated and unbound energy and passion with a swashbuckling abandon in the bravura of its composition.

In the process, it consigned to oblivion the rigid, ascetic and heavily “staged” paintings of Neoclassicism. It was a fitting allegory of the times.

Gericault was 27 when he painted the canvas. Though from a wealthy conservative family, throughout his short life he showed much empathy with the plight of the downtrodden.

The Raft has no heroes. Its protagonists are ordinary people abandoned and forced into extraordinary circumstances in which their moral failure and descent into barbarism predates nihilism, with its emphasis on the impotence of reason.

The dramatic contrasts between the light of flesh tones and distant sky and the dark tones of the dying, the shadow cast by the sail and the raft itself are mesmerising.

As the figures are life-size and when standing close the viewer is inevitably absorbed into this Dantean scene of anguish, dread and desperation. A rare achievement, indeed, for any painting of any epoch.

At the canvas’s centre stands the African Jean Charles, who waves a cloth to get the attention of a ship on the distant horizon. This arbitrary choice signal’s Gericault’s abolitionist beliefs — a Haitian friend posed for Charles. His figure is at the top end of the dazzling and consummate diagonal thrust of the composition that runs up from bottom left, from the dead to the living.

Gericault portrays the survivors in the shadow of the mast and persuaded his friend, the painter Eugene Delacroix — famous for the insurrectionist Liberty Leading the People of 1830 — to pose face-down, arm outstretched, for the corpse in the foreground.

The Raft of the Medusa remains a staggering and groundbreaking work of art. But it is worth noting that Gericault admired Michaelangelo’s Sistine Chapel fresco The Last Judgement, which includes a representation of Charon’s boat of lost souls, and the visual affinity with the Raft suggests a subconscious or deliberate inspiration for Gericault.

Over the last 200 years the influence of Gericault, and the Raft in particular, has been acknowledged by artists as diverse as Delacroix, Honore Daumier, Gustave Courbet, Edouard Manet, Max Ernst and today Frank Stella, Peter Saul and Jeff Koons.

JMW Turner, who must have been among the 40,000 who saw the canvas when it was exhibited  in London, must surely have had Gericalt in mind when he painted his fact-based and accusatory The Slave Ship (1840), a poignant argument for the abolition of slavery.

Though suffering from sciatica and depression, Gericault still manges in his late works an astonishing series of portraits of the mentally ill, the Monomaniacs.

As acutely insightful and emotionally honest as anything Rembrandt committed to canvas, only five of the 10 are accounted for after being discovered four decades after Gericault’s death at the age of 33 in 1824.