The 100-year-old mystery of the famous British explorer lost in the Amazon jungle

It has been described as "the greatest exploration mystery of the 20th century" with "the David Livingstone of the Amazon" at its heart. One hundred years ago today, a British explorer disappeared during an expedition to find an ancient lost city which he and others believed existed in the Amazon rainforest. Percy Fawcett, a geographer, cartographer, archaeologist and explorer of South America disappeared at the end of May 1925, along with his eldest son, 21-year-old Jack, and one of Jack's friends Raleigh Rimmel.

They had been looking for the Lost City of Z, a civilisation intertwined with the legendary El Dorado. After reading ancient legends and historical records, Fawcett had become convinced that Z must lie somewhere in the Matto Grosso region of Brazil. But the three men were never to return and their bodies were never found.

It is estimated that 100 would-be-rescuers died in more than thirteen separate expeditions sent to discover Fawcett's fate. Rumours emerged that the lost party had been killed by cannibals.

In one of his last letters written before he left England, Fawcett revealed he was concerned about the dangers of his mission and the effect that failure might have on his loved ones at their home in Stoke Canon near Exeter. "Physical death has no real terrors for me. I am only anxious about the family - and I know if I fail it probably means death," he wrote.

What happened on Fawcett's ill-fated last expedition has long fascinated historians and filmmakers. In 2016, The Lost City of Z starring Charlie Hunnam as Fawcett, Tom Holland as his son Jack and Sienna Miller as his long-suffering wife Nina was released to critical acclaim in cinemas. The film was co-written by journalist David Grann, an authority on Fawcett who wrote The Lost City of Z: A Tale of Deadly Obsession in the Amazon in 2009.

"He was the last of the great Victorian explorers who ventured into unchartered realms with little more than a machete, a compass and an almost divine sense of purpose," said Grann. "Fawcett had left instructions stating that if the expedition did not return, no rescue expedition should be sent lest the rescuers suffer his fate. His travel companions were both chosen for their health, ability and loyalty to each other."

On 20 April, 1925, Fawcett's final expedition departed from Cuiabá. The last communication from the expedition was on May 29 when Fawcett wrote, in a letter to his wife delivered by a native runner, that he was ready to go into unexplored territory with only Jack and Rimmel. They were reported to be crossing the Upper Xingu, a southeastern tributary river of the Amazon River.

The final letter, written from Dead Horse Camp, gave their location and was generally optimistic. Two years later in January 1927 the Royal Geographical Society declared the men lost. Soon after this declaration, a large number of volunteers offered to attempt to locate the missing explorers. None found them.

In his book, Grann recounts his own journey into the Amazon, by which he discovered new evidence about how Fawcett may have died and speaks to a woman, a little girl at the time, thought to be the last person to see them alive. Working from Fawcett's long-lost diaries, he reconstructed the explorer's last journey, including visiting members of the Kalapalo tribe in the Xingu Indigenous Park region of the state of Mato Grosso, Brazil. The Kalapalo had apparently preserved an oral history about Fawcett's small party of himself, his son Jack, and Jack's friend Raleigh Rimell, who were among the first Europeans the tribe had ever seen.

The oral account said that Fawcett and his party had stayed at their village and, despite warnings about "fierce Indians" who occupied that territory, had headed eastward. The Kalapalos observed smoke from Fawcett's expedition's campfire each evening for five days before it disappeared. As a result, the Kalapalos said they were sure that the "fierce Indians" had killed them.

Grann said: "Fawcett was certain that the Amazon contained a fabulous kingdom and he was not a soldier of fortune or crackpot. He was a man of science and he had spent years proving his case.Fawcett had determined that an ancient, highly cultured people still existed in the Brazilian Amazon and that their civilisation was so old and sophisticated it would forever change the Western view of the Americas. He had christened this lost world the City of Z."

Grann's book details the "merciless conditions" Fawcett faced including hostile tribesmen, piranhas, electric eels, jaguars, crocodiles, vampire bats and anacondas, one of which almost crushed him. In his reports to the RGS Grann discovered Fawcett had insisted that the snake was "longer than sixty feet." Thinking he had shot it dead, Fawcett stepped forward to slice off a piece of its skin to put in a specimen jar but as he cut into the anaconda "it jolted towards Fawcett and his party, sending them fleeing in fear."

Before he became an explorer Lieutenant-Colonel Percy Harrison Fawcett DSO was an artillery officer. Born in Torquay, on 31 August 1867, he was educated at Newton Abbot College according to the Torbay tourist board and then given a commission in the Royal Artillery at the age of 19.

He became a spy for the secret service in North Africa and served for many years in Ceylon, later renamed Sri Lanka, where he developed an interest in archaeology, before leaving the army to take up exploration on behalf of the Royal Geographical Society.

Fawcett made seven expeditions to between 1906 and 1924 - only interrupted by the First World War when he volunteered to lead an artillery brigade for which he was awarded the Distinguished Service Order (DSO). But his seventh expedition to the continent was to be his last. Some time after his disappearance, Percy's manuscripts and documents were later compiled by his younger son Brian and published in the best-selling book Exploration Fawcett in 1953.

Before he left England Fawcett had confided in his youngest son saying: "If with all my experience we can't make it, there's not much hope for others." Brian said his older brother Jack was "the reflection of his father, tall, frighteningly fit and ascetic."

Brian added that Jack's "six feet three inches were sheer bone and muscle and the his friend Rayleigh was similarly fit, the two boys had been inseparable since their childhood growing up in the Devon countryside.

David Grann sums up the story: "His feats came at a time when Britain, with the death of Queen Victoria and the rise of Germany, had grown anxious about its empire. The press seized upon Fawcett's accomplishments, portraying him like one of his childhood heroes and holding him up as the perfect counterpoint to the national crisis of confidence."

As for Fawcett he had, according to Grann, hoped to receive "the honour of immortality" and in some ways, thanks to our fascination with his incredible story, he has.