Back in the early 19th Century, an Irish adventurer and smuggler named Tom Johnson hatched a plot to rescue the exiled Napoleon from his island prison on St. Helena. But to do so he would need to approach the heavily guarded island with extreme caution. That’s when he decided to design his very own submarine — decades before the invention of the first practical underwater vessel.

This remarkable story comes courtesy of Mike Dash, an expert in 19th century European history. And it’s a story that really got started back in 1814 with Napoleon’s first banishment, an exile that saw him re-located to the small Italian island of Elba. But in a regrettable turn of events for his foes, Napoleon escaped and returned to France where he set up the famous Hundred Days campaign.

So, in an effort to really and truly be done with him, the British sent Napoleon to St. Helena in 1815 after his defeat at Waterloo.


But this time they meant business. St. Helena is a small island in the South Atlantic located about 1,200 miles from the nearest land. It’s also an island that features steep cliffs and has no viable landing places for boats. St. Helena was also guarded by the Royal Navy, along with a large garrison consisting of 2,800 men armed with 500 cannon. It was the perfect prison for the deposed Emperor — one intended to keep him there permanently.

The British were right to be worried that he’d escape. According to Dash, there’s enough historical evidence to suggest that this plan was very real. And in fact, Johnson likely devised the scheme after seeing a conceptual submarine design by Robert Fulton from 1806.


Called the Etna, the craft would have been 40 feet long and crewed by 34 men. It would also have been armed with torpedoes — something Johnston had every intention of adding to his version of the underwater machine.

Writing in the Smithsonian, Dash writes about the plot:

The narrative passes silently over the not inconsiderable difficulty of how such small vessels were to make the voyage south to St. Helena, and moves on to their appearance off the island — the Etna so close to the shore that it would need to be “well fortified with cork fenders” to prevent being dashed to pieces on the rocks. The plan then called for Johnson to land, carrying “a mechanical chair, capable of containing one person on the seat, and a standing foot-board at the back,” and equipped with the enormous quantity of 2,500 feet of “patent whale line.” Leaving this equipment on the rocks, the smuggler would scale the cliffs, sink an iron bolt and a block at the summit, and make his way inland to Longwood.

“I should then obtain my introduction to his Imperial Majesty and explain my plan… I proposed that [a] coachman should go into the house at a certain hour… and that His Majesty should be provided with a similar livery, as well as myself, the one in the character of a coachman and the other as groom…. We should then watch our opportunity to avoid the eye of the [naval patrols on] guard, who seldom looked out in the direction of highest point of the island, and upon our arriving at the spot where our blocks, &c., were deposited, I should make fast one end of my ball of twine to the ring, and heave the ball down to my confidential man…and then haul up the mechanical chair to the top. I should then place His Majesty in the chair, while I took my station at the back, and lowered away with a corresponding weight on the other side.”

The escape would be completed at nightfall, Johnson wrote, with the emperor boarding the Etna and then transferring to the larger Eagle. The two submarines would then make sail — they were to be equipped, Johnson’s account notes, with collapsible masts as well as engines. “I calculated,” he finished, “that no hostile ship could impede our progress…as in the event of any attack I should haul our sails, and strike yards and masts (which would only occupy about 40 minutes), and then submerge. Under water we should await the approach of an enemy, and then, with the aid of the little Etna, attaching the torpedo to her bottom, effect her destruction in 15 minutes.”

Unfortunately — or fortunately for Europe’s sake — Johnson’s plot was never realized. But even if he had reached Napoleon, Dash suspects that the deposed Emperor wouldn’t have gone for it:

There is no need to suppose that Napoleon himself had any inkling of a plan to rescue him; the scheme Johnson laid out in 1835 is so woolly it seems likely that he planned simply to try his luck. Such evidence as survives from the French side suggests that the emperor would have refused to go with his rescuer in the unlikely event that Johnson had actually appeared at Longwood; salvation in the form of an organized invasion was one thing, Bonaparte thought; subterfuge and deeds of desperate daring quite another. “From the start,” Ocampo says, Napoleon “made it very clear that he would not entertain any scheme that would require him to disguise himself or require any physical effort. He was very conscious of his own dignity and thought that being captured as a common criminal while escaping would be demeaning.… If he left St. Helena, he would do it ‘with his hat on his head and his sword at his side,’ as befitted his status.”

Indeed, Napoleon spent the rest of his days at St. Helena, dying in 1821.

There’s lots more to this incredible story at Smithsonian.

Images: The Smithsonian Institute.