When the infamous British smuggler Robert Jenkins sailed past Jamaica in April of 1731, he probably thought he was home free.

Jenkins had a ship full of contraband which he had picked up in the West Indies, and he was heading back to England to sell his goods in London’s premium markets.

But Jenkins wasn’t transporting drugs or alcohol, or even anything especially exotic. His ‘contraband’ was sugar. Big deal.

The West Indies at the time, though, were mainly under Spanish control. And Spain insisted that no one could export sugar from their territory without their express approval, along with paying heavy taxes and fees.

Most traders didn’t care. By 1731, Spain was a declining power. Everyone knew it. The once-dominant Spanish Empire had been vanquished by military defeat, political incompetence, succession crises, internal rebellion, and more, and it had become a hollowed out shell of its former self.

So even though it was technically illegal to export sugar from Spanish lands, British privateers and smugglers routinely thumbed their noses at the rules. After all, not only was Spain a declining power, but Britain was a rising power… so the Brits felt emboldened.

But luck was not on Jenkins’s side on that fateful day in April 1731. Somewhere off the coast of Cuba, his ship Rebecca was intercepted by a Spanish patrol boat named La Isabela.

Jenkins knew that his small vessel was outclassed, so he dropped anchor and permitted the Spanish to board his ship.

They quickly found the sugar… and we can only imagine Jenkins responding with a shrug of the shoulders and claiming “I have no idea how that got there.”

Whatever his response, the Spaniards were unimpressed. So they tied Jenkins to a mast and interrogated him for a while, until the Spanish commander finally drew his saber and sliced off Jenkins’ left ear.

Jenkins was then let go, and he hastily made his way back to London where he protested directly to King George II himself. There are even stories (though uncorroborated) that Jenkins even told his story in the House of Commons, waving his severed ear at shocked Members of Parliament.

Needless to say, Britain and Spain eventually went to war in what became known as the War of Jenkins’ Ear.

Jenkins wasn’t necessarily the primary cause. Tensions between the two kingdoms had been rising for years.

Britain was growing rapidly and wanted to muscle in on Spanish trade routes. Spain was shrinking and desperate to hold on to what it had.

War between rising and declining powers is actually a very common theme throughout history; it’s known as the Thucydides Trap, named after the ancient scholar who wrote the history of the wars between Athens and Sparta.

Athens and Sparta were also rising and declining powers in the 5th century BC. As Thucydides himself wrote, “the growth of power in Athens, and the alarm which this inspired in [Sparta], made war inevitable.”

World War I, which involved several rising and declining powers (Germany, the US, Austria-Hungary, the Ottoman Empire) was another Thucydides Trap.