When I moved to Chislehurst lately I discovered that many of my London friends had either never heard of the place, or thought it was by the sea – in Kent? Or was it Sussex? Gratifyingly it is now safely in the London Borough of Bromley, with all the transport links and economies that entails.

Another thing people often don’t know is that Louis Napoleon, nephew of the great Napoleon, who became Napoleon III, Emperor of the French, came to live in Chislehurst after he was thrown out of France in 1870 following his defeat at the Battle of Sedan. He and his Empress, the glamorous Spanish Countess Eugénie de Montijo, took up residence in a fine Georgian house, Camden Place, which had recently been tarted up in a high Victorian style and was a reasonably suitable setting for their retired Imperial lives. But Louis Napoleon died a couple of years later, leaving Eugénie a grieving widow with her son Louis, who was immediately given the title of Napoleon IV – though this was never officially proclaimed. The French artist James Tissot, one of several famous artists who like the Royals fled from the Paris Commune, painted them together in the grounds of Camden Place, in deep mourning, some courtiers also in black hovering among autumn trees at a discreet distance.

There was an international send-off for the ex-emperor, and Eugénie laid him to rest in a grand tomb in a newly-built mortuary chapel attached to the little Catholic church of St Mary’s on the edge of the village. And now what were Eugénie and young Louis, aged only nineteen, to do with themselves? Louis knew exactly what he wanted: to join the army and engage in glorious military adventures. He had already had a taste of war, accompanying his father to the fighting on the German frontier, though when things turned nasty he had been summarily removed from danger and packed off to England.

He badgered his mother, who badgered Queen Victoria, who badgered the military top brass, and although Louis was not accorded a commission, he was allowed to join the army in Zululand, where a splendid war was taking place. It was 1879, and one of the most glorious of the army’s defeats occurred that year, at Isandlhwana where a whole regiment was wiped out by the Zulus. The disaster became the stuff of schoolboy legend: as is well known, the British (or the English at any rate) rather prefer an embarrassing military rout than a good honest victory (think of the Light Brigade at Balaclava). Louis avoided all that, and wasn’t in the least deterred by the horror of it. He was still itching for glory – it was in the Bonaparte blood – and one afternoon, with the permission of Col Richard Harrison of the Royal Engineers, and defying Lieutenant Jahleel Brenton Carey who was officially in charge of him, rushed out into the veldt with a scouting party. His senior officers thought there was no danger, but the party was attacked and he was struck down by a little band of the enemy who happened to be on the prowl at the time. He fought bravely, and suffered eighteen separate wounds, including one from an assegai that penetrated his brain. Afterwards, the Zulus protested that if they had known who Louis was they wouldn’t have killed him.

The news reverberated across Europe. It was a devastating blow not only to his mother, but to many who harboured ambitions to restore him to the French throne. His body, in a state of severe decomposition, was shipped back to Woolwich, and he was buried next to his father in the little church in Chislehurst. A fine alabaster effigy of him in his uniform is still there today, with a neat tablet commemorating his adventure in Latin.

A huge Celtic cross, carved from Cornish granite, was shortly afterwards erected on the Common nearby, adorned with the Bonaparte bees and a touching message from the Prince thanking Queen Victoria and “the dwellers at Chislehurst” for their kind hospitality. But this didn’t satisfy Eugénie. She had in mind a truly magnificent memorial to both her husband and her son, and requested a neighbouring landowner, a Mr Edlemann, to sell her a field in which she could realise that ambition. Mr Edlemann was an ardent Protestant and would have no truck with this Papistical foreign vanity. He refused the Empress’s request. She duly bore off the remains of both deceased family members to St Michael’s Abbey in Farnborough, Hampshire, and built a sumptuous mausoleum for them there, where in due course she too was interred.

She was ninety-four when she died in 1920, and one can’t help wondering what would have become of her son if he had survived. He would have had no chance of realising his ambitions, military or political, and would have mouldered on, an embarrassing appendix to French history, no doubt attracting Bonapartist nutters and hotheads, a focus for misplaced Imperialist romance. It was surely as well that he died earning a semblance of military glory, as he had wished. As Sir Garnet Wolseley bluntly observed, “he died a soldier’s death. What on earth could he have done better?” His senior officers were much blamed, and Lt Brenton was duly, and one feels a little unfairly, court-martialled and doomed to lifelong ignominy for failing to keep him firmly under control.

It’s a poignant tale, touching and sad, but in some ways oddly satisfactory. What the little Corsican would have thought of his grand-nephew, Napoleon IV, the last of the line, fighting the Zulus in the British army, one hesitates to imagine. No doubt he is still revolving in his own grandiose tomb in the Invalides.