1. The Pig War

George Pickett—leader of American forces during the Pig War. (Credit: Getty Images)

The aptly named Pig War nearly saw an argument over a slaughtered swine lead to a full-scale conflict between the United States and Great Britain. The controversy began in 1859 on San Juan Island, a chunk of land located between the mainland United States and Vancouver Island. At the time, the island was home to American settlers and British employees of the Hudson’s Bay Company, and both parties had laid claim to its fertile soil. The first and only shots of the Pig War came on June 15, 1859, when an American farmer named Lyman Cutlar gunned down a British-owned black boar after he discovered the animal rooting through his potato patch. The ensuing argument over the dead hog increased tensions between the two groups of settlers, and Cutlar was eventually threatened with arrest.

After the Americans reported the incident to the military, the U.S. Army dispatched Captain George Pickett—later a Confederate general during the Civil War—to San Juan with a small complement of troops. Pickett upped the ante by declaring the whole island U.S. property, and the British responded by sending a fleet of heavily armed naval vessels to the coastline. An absurd standoff ensued, and the situation remained on a knife-edge for several agonizing weeks. The two nations would finally negotiate a deal allowing for joint military occupation of San Juan Island in October 1859, ending the Pig War as a bloodless stalemate—save for one unfortunate hog.

2. The Nika Riot

Circus and hippodrome at Constantinople (Credit: Getty Images)

In 532 AD, massive mobs flooded the streets of Constantinople, burning large parts of the city and nearly toppling the government of the Emperor Justinian—and all of it in the name of chariot racing. The races held at Constantinople’s hippodrome had soared in popularity during the sixth century, and fans had organized themselves into strict factions. These ancient hooligans acted more like street gangs than sports fans, and the most powerful groups—known as the Blues and the Greens—became notorious for their barbarism.

Conflict erupted in January 532, when Emperor Justinian refused to release two members of the Blues and Greens who had been condemned to death. In a rare instance of unity, the two factions banded together and began to riot. In a few short days, they had burned the headquarters of the city prefect, clashed with imperial guards and even attempted to crown a new emperor. Faced with a full-scale revolution, Justinian finally resolved to put down the rebellion by force. After bribing the Blues to gain their support, the emperor launched a devastating assault on the remaining hooligans. By the end of the attack, the riots had been quelled and some 30,000 members of the mob lay dead around the grounds of the hippodrome.

3. The War of the Stray Dog

Picture of Petrich incident from French newspaper (Credit: Getty Images)

In one of the most bizarre conflicts of the 20th century, a dog inadvertently triggered an international crisis. The incident was the culmination of a long period of hostility between Greece and Bulgaria, which had been at odds since the Second Balkan War in the 1910s. Tensions finally boiled over in October 1925, when a Greek soldier was shot after allegedly crossing the border into Bulgaria while chasing after his runaway dog.

The shooting became a rallying cry for the Greeks, who soon after invaded Bulgaria and occupied several villages. They were even set to commence shelling the city of Petrich when the League of Nations finally intervened and condemned the attack. An international committee later negotiated a ceasefire between the two nations, but not before the misunderstanding had resulted in the deaths of some 50 people.

4. The War of Jenkins’ Ear

Painting of the capture of Porto Bello

In 1738, a British mariner named Robert Jenkins displayed a severed, decomposing ear before the members of Parliament. As part of a formal testimony, he claimed that a Spanish coastguard officer had sliced off his ear seven years earlier as punishment for smuggling. Spurred on by this stirring testimony, the British had soon declared war on the kingdom of Spain. Thus began the outlandish “War of Jenkins’ Ear.”

In truth, a clash between the British and Spanish had been in the works since the beginning of the 1700s, and Jenkins’ missing ear merely served as a convenient catalyst. The conflict had its roots in territorial disputes over the border between Spanish Florida and British Georgia, as well as the Spanish of boarding and harassing English vessels like the one captained by Jenkins. Fighting began in late 1739, and continued for two years in Florida and Georgia, with neither side emerging as the clear victor. The conflict later merged with the more expansive War of the Austrian Succession, which would not end until 1748.

5. The Toledo War

Toledo, Ohio, in the late 1800s (Credit: Getty Images)

Michigan and Ohio might now be known their longstanding football rivalry, but the two states once nearly went to war over a border dispute. The argument began in 1803, when the newly formed state of Ohio took ownership of a sliver of land containing the town of Toledo. Michigan territory later disputed Ohio’s claim on this “Toledo strip” in the 1830s, launching a heated debate that teetered on the edge of violence for several weeks.

In what became known as the Toledo War, both sides wrestled for political control of the territory, and both raised militias to defend against a possible invasion by the other. Desperate for Ohio’s valuable electoral votes, President Andrew Jackson finally intervened in 1835, and by 1836 a compromise was sealed. The détente saw Michigan territory relinquish its claim on the Toledo strip in exchange for statehood and a portion of the Upper Peninsula. Many viewed the decision as a grave injustice, but some residents of the disputed region were quick to accept their newfound status as Ohioans. When one woman learned of the decision, she is said to have quipped, “Thank the Lord, I never did like that Michigan weather anyway.”

6. The Pastry War

Picture of the taking of citadel San Juan de Ulua. (Credit: Getty Images)

In 1828, angry mobs destroyed large parts of Mexico City during a military coup. One of the victims of the rioting was an expatriate French pastry chef named Remontel, whose small café was ransacked by looters. Mexican officials ignored his complaints, so Remontel petitioned the French government for compensation. His request sat unnoticed until a decade later, when it came to the attention of King Louis-Philippe. The king was already furious that Mexico had failed to repay millions in loans, and now he demanded they pay 600,000 pesos to compensate the pastry chef for his losses. When the Mexicans balked at handing over such an astronomical sum, Louis-Philippe did the unexpected: He started a war.

In October 1838, a French fleet arrived in Mexico and blockaded the city of Veracruz. When the Mexicans still refused to pay up, the ships began shelling the San Juan de Ulua citadel. A few minor battles followed, and by December as many as 250 soldiers had been killed. The famous general Santa Anna even came out of retirement to lead the Mexican army against the French, and he lost a leg after he was wounded by grapeshot. Fighting finally ended in March 1839, when the British government helped broker a peace deal. As part of the treaty, the Mexicans were forced to shell out the 600,000 pesos—no doubt a large sum for a pastry shop at the time.