The Great Fire of London of 1666 destroyed almost the entire Old City of London. The fire broke out in the early hours of Sunday morning, September 2, 1666, in the basement of a baker’s shop in Pudding Lane owned by a gentleman named Thomas Farriner. Although Farriner initially claimed to have extinguished the fire in his bakery himself, it soon burned out of control, and with such ferocity and speed that it quickly proved all but impossible to hold back.

The fire went on to burn for more than three days, at which time more than 13,000 homes, some 87 churches, and more than 40 livery and trade halls across London were reduced to ashes. The original historic gates of the City of London were severely damaged, as too was the city’s main Guildhall, the original St. Paul’s Cathedral, and the Royal Exchange—in some instances, beyond all repairs. There was one silver lining, at least: Though accounts of the disaster vary, the human toll of the fire is alleged to have been relatively small. Within a few years of the blaze, the English writer Edward Chamberlayne explained that while much of the city was destroyed, “not above six or eight persons were burnt.”

There was, however, at least one death that could be indirectly attributed to the fire—namely, that of a bizarre and tragic character that was executed in the aftermath of the blaze for having claimed to have started it.

Born in Rouen, in northern France, in 1640, Robert Hubert was a watchmaker by trade. Although details of his life are sketchy at best, Hubert is believed to have spent much of his adult life living and working in London, although he spoke little English and likely divided much of his time between Britain and the Continent. Indeed, on the night that the Great Fire of London first broke out, Hubert was not even in England but instead on board the Maid of Stockholm, a North Sea ferry that had been traveling between Sweden—where Hubert had reportedly been visiting relatives— and his native France.

At the time of the fire, England was engaged in the Second Anglo-Dutch War, a bitter and long-lasting conflict with the Kingdom of the Netherlands. Ultimately, any non-English vessel (or, for that matter, any non-English national) that happened to stray into English waters was viewed with considerable suspicion. As a result, the Maid of Stockholm was intercepted on August 31 on its return journey back across the North Sea from Sweden, and forcibly redirected to London. There, its passengers and crew would have to remain in limbo, awaiting permission from the city’s authorities to continue their journey on to France. They arrived in London on September 3 to find the entire city ablaze.

All of those on board the ship—including its captain, known only as a Mr. Peterson—stood on the deck of the ship watching helplessly as the disaster unfolded before their eyes. And it was there that Captain Peterson reportedly overheard Robert Hubert muttering softly and repeatedly to himself the words, “Very well, very well! Yes, yes!” As he watched the city being burned to the ground. Hubert’s behavior proved disconcerting, and with the cause of the fire at that time unclear—and with an air of suspicion already rife in the city due to the ongoing war—Peterson became concerned that Hubert may be a spy, a traitor, or else in some way involved in the city’s destruction.

Later accounts of Hubert’s life and personality have suggested that he may have suffered from some sort of mental illness, or perhaps even a condition similar to what would be known as Tourette’s Syndrome today. That would certainly explain his seemingly unconscious muttering on the deck of the Maid of Stockholm, and why Captain Peterson might have become so unnerved by his behavior. Either way, Hubert’s mumbling proved upsetting enough to see him thrown below deck and imprisoned in the hold of the Maid of Stockholm on Captain Peterson’s orders. Early the following morning, however, Hubert somehow managed to escape the ship’s hold and fled onto the Thames dockside by jumping down from a small hatch window in the captain’s quarters. Captain Peterson himself later testified that he saw Hubert flee along the quayside, and vanish into a crowd.

When news of Hubert’s curious behavior and clandestine escape from the Maid of Stockholm became known, the London authorities soon presumed that he must have somehow been involved in the fire. A week later, on September 11, 1666, he was arrested in Romford, a town around 12 miles east of the city of London, and taken into custody. Precisely what happened to him while he was under arrest remains unclear, but by the time Hubert appeared in court in London several days later, a strange and wholly inconsistent confession had been extracted from him.

According to Huber’s testimony, he claimed to have started the fire by throwing a makeshift grenade through a window in Thomas Farriner’s bakery. The fact that the fire broke out two days before Hubert and the Maid of Stockholm even arrived in the city was paid little heed—as was the fact that Thomas Farriner’s bakery had no windows through which a grenade could be thrown. Nevertheless, despite the obvious holes in Hubert’s testimony, his confession sealed his fate: the court had their scapegoat, and Hubert was sentenced to death. On October 27, 1666, he was taken out to the Tyburn gallows in London and hanged. And with that, the Great Fire of London had claimed its final victim—nearly two months after it had been extinguished.