Like many strange stories, this one starts with Alexander the Great.

‘Tell me, where is the tomb of Alexander?’ asked the writer and archbishop of Constantinople, John Chrysostom, at the end of the third century AD. ‘Show me, tell me the day on which he died.’ For over 1,500 years, travellers and tricksters, scholars and fortune hunters have wondered: where does the body of Alexander, the most elusive corpse in history, lie? The tomb of Alexander was one of the most famous monuments of the ancient world: emperors and pharaohs paid it homage for over 600 years. (The young Augustus, it was said, broke off a piece of Alexander’s nose when he visited). Then Alexander’s tomb disappeared: no-one knows exactly how, or why – but that has not stopped people dreaming of it, and searching for it.

Every story about Alexander is an uneasy balancing act between scholarship and fraud, fact and fiction. And few people have ever embodied that balancing act as fully, or as maddeningly, as Edward Daniel Clarke. Largely unknown today, his story is a remarkable and revealing one. It is a messy, often infuriating tale – but it also reveals how history gets written, how world-changing discoveries happen, and how our knowledge of the past comes to be. It features an extraordinarily mendacious scholar, a mysterious sarcophagus, and a lot of looting. And it begins in 1801, when Edward Daniel Clarke came to Egypt, following a victorious British army.

Clarke was an intellectual omnivore: endlessly, gleefully curious. ‘The old adage of “too many irons in the fire,”’ he once wrote, ‘conveys an abominable lie. You cannot have too many; poker, tongs, and all – keep them all going.’ Clarke was a classicist, scientist, traveller, and dabbler. One day, he was peering into pyramids. The next, he was blowing up large parts of Cambridge University with his science experiments.

‘Having blown off both my eyebrows, and eyelashes, and nearly blown out both my eyes,’ he wrote, ‘I ended with a bang that shook all the houses around my lecture room.’

Clarke came from a time before scholarship was specialised. He was a collector of the world, an enthusiast for the ages. He set out from Cambridge on his travels in 1799; 1801 found him in Egypt, and in the middle of a war between Britain and France.

The British had just cut off Napoleon’s army in Alexandria. But Napoleon didn’t just send soldiers to Egypt. He sent a large party of intellectuals: scholars of every description, who were tasked with understanding France’s new conquest. They immediately set to work, looting everything in sight. Sarcophagi were carted off, columns were pulled down, tombs were pried open, and obelisks chopped off.

Now, the British planned to loot the French. And Clarke – one of the few British scholars within a thousand miles – was put in charge. A satirical print of the time by caricaturist James Gillray imagined the French intellectuals huddled at the top of an ancient column, desperately trying to keep hold of their hoard. ‘Dogs would not range better for game,’ Clarke wrote gleefully, ‘than we have done for Statues, Sarcophagi, Maps, Manuscripts, Drawings, Plans, Charts, Botany, Stuffed Birds, Animals, Dried Fishes, etc.’

The French, however, were outraged. The French commander in Alexandria, General Menou, said: ‘You may tell your Commander-in-Chief that he has as much right to make this demand as a highwayman has to ask for my purse! He has a cannon in each of my ears and another in my mouth; let him take what pleases him. I have a tolerable stock of shirts, perhaps he may fancy some of these!’

Clarke’s haul eventually made its way back to London. Today, it forms the heart of the British Museum’s Egyptian collection. Almost every work was astonishing. But most prized of Clarke’s finds was a sarcophagus with an extraordinary story behind it. Clarke claimed that it had once been the final resting place of history’s greatest conqueror, Alexander the Great.

The sarcophagus was an enormous thing: made of heavy black granite, and covered with hieroglyphic inscriptions which no-one was able to read. The story Clarke told of how he had acquired it was remarkable.

One day, a party of merchants came to meet with him in Alexandria, and ‘speaking with great circumspection and in a low voice,’ their leader asked Clarke: ‘Does your Commander in Chief know that they [the French] have the Tomb of Alexander?’

Clarke’s jaw dropped. He begged the merchants to tell him more. They said that Alexander’s sarcophagus was ‘a beautiful green stone,’ taken from a mosque in the heart of the old city. The merchants told Clarke of the extraordinary care the French had taken to keep secret any whisper of what they had found. Alexander’s sarcophagus was now ‘in the hold of an hospital ship, named La Cause, in the inner harbour; and being provided with a boat, there we found it, half filled with filth, and covered with the rags of the sick people on board.’

Could the sarcophagus really be Alexander’s?

When Clarke got back to Britain with his finds, he wrote. The Tomb of Alexander landed in bookshops with a thud in 1805. Clarke announced that he had solved one of history’s greatest mysteries – and, along the way, saved Alexander’s sarcophagus from the dastardly clutches of Napoleon. The French emperor had (Clarke claimed) hoped to be buried in the sarcophagus himself.

Needless to say, Clarke’s claims provoked a reaction. He was accused of ‘temerity’ and ‘honest or clumsy simplicity.’ Reviewers complained that he ‘tortured sources, as if they were martyrs.’

But many people believed him. Stranger things had happened at the British Museum, after all. One Victorian novel even suggested that the Museum had the original Ten Commandments hidden in a back room.

But the museum itself was not convinced. While it put the sarcophagus on display, it was not labelled as Alexander’s. Clarke was furious. ‘Why does the Museum not call it the tomb of Alexander?’ he wrote. ‘Why has the evidence of its discovery been suppressed?’ Clarke threatened to leaflet visitors to the British Museum if the directors did not change their tune.

The controversy rumbled on for years. It was only resolved when, thanks to the Rosetta Stone, the hieroglyphs on the sarcophagus were deciphered, later in in the nineteenth century. Needless to say, it did not actually belong to Alexander. It was made for an Egyptian pharaoh, Nectanebo II. Clarke’s wild hunch was wrong.

But something more serious was also wrong with Clarke’s story. His tale of how he had come upon the sarcophagus in Alexandria – the whispers from the merchants, the frantic hunt, the discovery of Alexander’s resting-place in the bowels of a hospital ship – was almost certainly not true.

Let’s go back to Alexandria in 1801. Clarke is on the hunt: seizing every ancient artefact he can get his hands on. Yet, in his letters and diaries, he mentions nothing about discovering Alexander’s tomb. ‘Nothing abounds except dust, mosquitoes, bugs, and lice,’ he complained.

On his way home to Britain, Clarke still had nothing to say about his discovery of the sarcophagus. But he was very proud of acquiring something else. ‘The tomb of Euclid (you will hardly credit it!),’ he wrote gleefully, ‘I bought it of a consul, from under the very nose of the German ambassador.’ Euclid of Alexandria, the famous ancient mathematician, had nothing whatsoever to do with Alexander the Great.

But the ‘tomb of Euclid’ never made it back to Britain. It was shipwrecked and lost along the way. And, soon after he heard the news, Clarke seems to have started telling the story of his miraculous discovery of ‘Alexander’s tomb.’

Almost Clarke’s entire story, in other words, appears to have been made up. As long as Clarke had a famous tomb tucked under his arm when he got back to Britain, he did not care whose it was: Euclid, Alexander, anyone would do.

This should be the moment when Clarke is dismissed: not just a looter, but a liar. But Clarke didn’t just bring his dubious sarcophagus back to London. He also brought a smaller object. Today, it too is on display in the British Museum. You’ll know it when you see it. It’s the one with the giant crowd around it: the Rosetta Stone.

Edward Daniel Clarke, dreamer, looter, pyromaniac, fantasist, brought back from Egypt the single most important find in the history of Egyptology, the key to deciphering ancient Egyptian languages.

Clarke ended his life as a pillar of the British establishment. Cambridge does not normally indulge in extravagant mourning, but they made an exception for Clarke. ‘The tears of genius,’ it was said, ‘have been shed around his tomb.’

The history of scholarship has a dirty little secret. It’s full of people like Edward Daniel Clarke. The most profound discoveries are often made by the messiest people. Scoundrels. Gin-fiends. Creeps. Frauds. People who do things conventional scholars wouldn’t dream of.

As for the bones of Alexander, if they still exist, they are still waiting to be discovered. Almost every year, another candidate for Alexander’s tomb hits the headlines. And then the evidence falls apart. The tale turns out to be a little too tall.

Alexander makes dreamers of us all. But if you look closely at the tallest tales, sometimes – just sometimes – you’ll glimpse history shining straight through them.

There is one final twist to this tale. Nectanebo II, the pharaoh whose sarcophagus Clarke brought back from Alexandria, was famous for one thing above all: a legend that made him the true father of Alexander the Great.

‘Many say that Alexander was the son of King Philip of Macedon, but they are liars,’ the tale – known as the Alexander Romance – begins. ‘This story is untrue. Alexander was not Philip’s son. The wisest of the Egyptians know that he was the son of Nectanebo of Egypt.’ Nectanebo was a magician, and a liar to rival Edward Daniel Clarke. He prophesised to Alexander’s mother that the Egyptian god Amun would visit her bed. Then, that night, he put on an improvised disguise and swaggered into her bedroom, dressed as Amun.

The next morning, when Alexander’s mother awoke, she went looking for Nectanebo. ‘Tell me, magician,’ she said to him, ‘when will the god come to me again? For he was very sweet to me.’

Even in the British Museum, you don’t expect to stumble across the tomb of a legendary sorcerer. But there the sarcophagus sits today, in the Egyptian galleries, across from the Rosetta Stone. Recently, another scholar, Andrew Chugg, has taken up Edward Daniel Clarke’s lonely battle: determined to prove that the sarcophagus, despite all evidence to the contrary, was Alexander’s after all. As Edward Daniel Clarke’s story reminds us, sometimes truth really is stranger than fiction.