Robert Fisk: The mystery of the man who shot Nelson

Against advice, Horatio is wearing his many decorations. Talk about asking for it

I've always been possessed of the idea of finding the man who fired the shot that killed another man. During the Lebanese civil war, I spent days trying to find the Phalangist gunner who sent a shell into the Hamra area of west Beirut, slaughtering a group of civilians. But I never learned who he was. I did, in 1996, track down the makers of a missile which an Israeli helicopter fired into an ambulance full of women and children refugees in southern Lebanon. I actually met them at their Boeing offices in Duluth in the US state of Georgia, and laid fragments of their exploded Hellfire AGM missile on the boardroom table (along with pictures of the dead and wounded children). The explosion that followed was slightly louder than the one in Lebanon. Outrageously, the Boeing advertiser's slogan for its Hellfire at arms fairs was "All for one and one for all".

I wrote at the time that if anyone had ever turned over in their grave, it must have been Alexandre Dumas. D'Artagnan and the three musketeers never uttered their famous rallying call while attacking refugees. But from that very same grave, Dumas has returned with a "lost" novel, The Last Cavalier which really does take me to the man who fired the shot that killed another man.

It's a long read with, of course, absolutely no sex but an awful lot of violence – here I declare an interest, by the way, since it has been brought out by the publishers of my own books – but towards the end, the French hero does something extraordinary. He shoots Admiral Horatio Nelson. Yes, Hector, the Count de Sainte-Ermine, masquerading under the name of René, takes aim from the 74-gun French warship Redoubtable at the Battle of Trafalgar, when he identifies Nelson who – against sensible advice from his fellow officers – is wearing on his uniform the decorations of the Order of the Bath, the Order of Ferdinand, the Order of Merit, the Order of Malta and the Ottoman Crescent. Talk about asking for it.

Dumas had obviously done his homework, for Nelson dies according to all the historical accounts, nursed by his sorrowing doctor, insisting that he attends to the other wounded, pleading that Emma Hamilton be cared for along with his baby daughter Horatia, kissed by Hardy, dying with those last imperishable words: "Thank God, I have done my duty." René, however, is subsequently taken prisoner but saves a British ship, HMS Samson – which seems to be as fictional as the hero held aboard it – when it is in danger of being swamped in the vast storm which the dying Nelson had predicted.

Nelson's immense valour must be weighed against his equally cruel and non-fictional assistance in the subjugation of the Jacobins of Naples in 1799. He ordered one officer to be hanged from the yard-arm for attacking both royalist and British ships, his body thrown into the sea. The unfortunate man – a certain Francesco Caracciolo, duke of Brienza – popped up a few days later, his decomposing head above the waves, moving steadily towards the shore. Nelson later assisted in dispatching hundreds of prisoners – well-bred ladies among them – to the drumhead royalist courts after which they were hanged before baying mobs. Not for nothing is the hero of Trafalgar also known as the Butcher of Naples.

And then there was his extraordinary vanity. I cannot beat Jan Morris's wonderful description in this newspaper 14 years ago. "What a perfect ass the Saviour of Europe could be! How preposterously he swaggered around with his stars and his medals and his sashes and his scarlet pelisse and the 'chelengk' on his cocked hat, given him by the Sultan of Turkey, whose diamond centre revolved when you wound it up!"

And Nelson would have approved, I think, of the grim little souvenir of his death which I went to look at one Sunday morning last month in the Grand Vestibule at Windsor Castle. For there behind a thick magnifying glass lies the shattered musket ball dug from Nelson's body on HMS Victory by his surgeon, William Beatty. It is a pale, grey feathery thing, a minuscule piece of material attached to it which perfectly matches the hole in the uniform that Nelson was wearing on 21 October 1805 – so much for the other eight musket balls around, each of whose owners claim them to be the genuine article.

But who did shoot Nelson? Well, Christopher Hibbert's biography intriguingly quotes from a certain Colonel John Drinkwater, who had served with Nelson aboard the Minerva in 1797. Drinkwater states that "a humble sharp-shooter" shot Nelson and goes on to recall that the acquaintance of a friend had later employed in Paris a French artificer who was aboard the Redoubtable at Trafalgar and that the artificer was a friend of the man who killed Nelson. Yes, this sounds a bit much, but that is the nature of 19th-century journalism.

Well, according to the friend of the artificer, the sniper assumed from his medals that Nelson was an admiral and climbed aloft carrying four musket balls while memorably declaring, in slightly quaint French: "Si je ne le tue pas de ces trois, je me brûle la cervelle avec la quatrième." – "If I don't kill him with these three, I'll blow out my brains with the fourth." This isn't quite as robust as "England expects that every man will do his duty" – but then again Nelson originally wanted the signal to read "England confides that every man will do his duty". It was changed after an officer pointed out to him that "confides" was not in the signal book and would have to be ordered letter by letter. The grouchy Admiral Collingwood was not amused. "What is Nelson signalling about?" he asked. "We all know what we have to do."

So did Dumas know the story of the sniper? Drinkwater published his book in 1840 and Dumas was working on The Last Cavalier when he died in 1870. The book has been put together by assiduous rereading of a massive but forgotten serial he wrote for an equally long-forgotten French newspaper called Le Moniteur. But surely, if he was aware of Drinkwater, he would have included that line about the fourth musket ball. But maybe it was a little too lowly to put in the mouth of a French count like René. I guess it's just a matter of all for one and one for all. But thank God they didn't have air-to-ground missiles at Trafalgar.

Robert Fisk is giving a talk at Tuke Hall, Regent's College, London, 21 May, 7pm. Details at www.seminars.ie; 0800 404 7326