The real-life Captain Kurz: French army captain who turned from promising officer to war criminal

He is one of twentieth century literatures’ most notorious characters, a petty tyrant corrupted by his colonial powers.

Seen as one of author Joseph Conrad’s most memorable creations, it had long been assumed that ivory trader Kurtz, a central figure in his 1899 novella Heart of Darkness, had been conjured from his imagination.

Now however a new BBC documentary is set to suggest that Kurtz – later memorably played by Marlon Brando in the 1979 American war film loosely based on the novel, Apocalypse Now – may have been based on captain Paul Voulet, a real-life renegade army captain.

Like the fictional Kurtz, Voulet was stationed in Africa in the late 19th century, where, turning rogue, he oversaw the massacre of thousands of native people.

His story is told in African Apocalypse which, via fascinating archival letters and pictures, traces Voulet’s unsettling transformation from promising young French soldier to depraved war criminal.

Until now Conrad’s inspiration for Kurtz had remained a literary mystery, for while it was the author’s own journey up the Congo that laid the groundwork for his fourth and most infamous book, he met no such character during his time there.

While researching the film, director Rob Lemkin discovered that shortly before he wrote Heart of Darkness, Conrad had gone to stay at the home of Cora Stewart, the estranged wife of Captain Donald Stewart, then the British representative in West Africa, Captain Donald Stewart.

A direct contemporary of Voulet in Africa, Stewart had made plain his dismay at his French arch-rival’s conduct in top secret dispatches to the Prime Minister Lord Salisbury, reporting his repeated breaking of international treaties , including taking women and children as ‘prisoners of war’ and selling them into slavery to pay his mercenaries.

The captain’s reports were classified, but Cora was aware of their content and as Conrad went to stay at the home Cora now shared with his close friend, Novelist Stephen Crane, it is not unlikely that she related Voulet’s depraved exploits.

The rogue officer’s exploits certainly mirror the plot and details of Conrad’s story. Crowned Soldier of the Year in Paris in 1898, Voulet was handpicked to secure the forbidding and hostile lands east of the Niger, tasked with taking control of Lake Chad and unify the French territories in West Africa.

Yet quickly drunk on power, he soon turned into a depraved war criminal, ordering his mercenaries to massacres hundreds of locals and overseeing the raping and pillaging of countless victims.

His soldiers were paid to kill and would chop the hands off their victims as proof of each execution, their names , alongside the payments he had made, kept in a macabre list by Voulet.

Many would be decapitated, mirroring the severed heads around the Congo home of Conrad’s Kurtz – a manifestation of the character’s descent into madness.

Not content with his exploits in West Africa, from there Voulet called on his troops to follow him to the east to create the most powerful empire in Africa, telling them ‘I am no longer French, I am a black Emperor, greater than Napoleon’.

But the mercenaries soon decided that their commander had lost his mind.

They murdered him and buried his body in a remote Sahel village where his grave can still be found today.

Two months later Voulet’s heavily censored story was told in the same literary magazine, where earlier that year Conrad’s unsettling novella had just been published in three parts.

Whether or not stories of Voulet were in his mind at the time of writing cannot be proved – but that the journeys of Kurtz and Captain Paul Voulet to the Heart of Darkness are uncannily similar.

• BBC Arena: African Apocalypse – BBC2 – Saturday May 22 at 9.30pm