The longest presidential inauguration speech in U.S. history was given by William Henry Harrison when he took over from Martin Van Buren on March 4, 1841. Lasting a full hour and 45 minutes, the almost 8500-word speech was delivered amid a blinding snowstorm without a coat or hat to keep out the cold. Harrison's doctors blamed pneumonia caught that day for the president's death 31 days after taking office, though modern medical experts think the culprit was more likely enteric fever.

Whatever its cause, Harrison’s untimely death caused a brief political crisis, since it seemed unclear whether the president’s successor, Vice President John Tyler, should remain in power for Harrison’s full term or operate as acting president until a new election could be held. In the end, Tyler remained in office for the rest of Harrison’s term, becoming the United States’ third president in a single year. A similar situation emerged 40 years later, when James A. Garfield replaced Rutherford B. Hayes in March 1881 only to be replaced, after his death the following September, by Vice President Chester A. Arthur.

As tumultuous as these years were, they certainly aren’t the only in history to have seen an unusually quick turnaround in the highest offices in the land.

1. ANCIENT ROME, 69 C.E.

Shortly after Nero committed suicide in 68 C.E., the Roman Empire was thrown into a rocky 12 months known as The Year of the Four Emperors. Initially Nero was succeeded by the Roman governor Galba, but Galba soon proved just as unpredictable and as unpopular as his predecessor. As his reign became increasingly tyrannical (he had a habit of executing any senator he distrusted), he adopted a successor, slighting his longstanding supporter Otho, who subsequently arranged to have Galba and the successor assassinated on January 15, 69. Otho was crowned the same day, but Galba’s seven-month rule had caused such unrest across the empire that the northern province of Germania had already turned its back on Rome and appointed its own ruler, Aulus Vitellius—who now had his sights set firmly on the Roman throne.

In April, Vitellius marched his armies south, defeated Otho in battle, and swept to power. In celebration, he supposedly began spending so lavishly on parades and banquets in honor of himself that his entertainment bill alone almost bankrupted the state. But when his actions were questioned, he is said to have had his advisors, moneylenders, and debt collectors tortured and executed.

Once again, unrest spread throughout the empire, and in frustration many of the eastern provinces proclaimed Vespasian, one of Rome’s most successful generals, their new emperor. In December, an alliance of forces loyal to Vespasian met Vitellius’s dwindling supporters in battle at Cremona and ensured Vespasian’s successful march on Rome. After a short time on the run (with two of his chefs alongside him), Vitellius was caught, killed, and his body dumped in the Tiber. Vespasian took to the throne as the year came to an end, and quickly set about restoring some much-needed stability.

2. ENGLAND, 1016

Ethelred the UnreadyWikimedia Commons // Public domain

When the Saxon king Ethelred the Unready died on April 23, 1016, his 26-year-old son Edmund Ironside was elected to succeed him. He immediately faced the same struggle that had dogged his father’s final years: In the north of England, vast swathes of territory were being invaded and claimed by the Danish king Cnut the Great.

In the months that followed, Edmund’s armies clashed repeatedly with the Danes in a series of bloody but inconclusive battles, until finally a truce was agreed upon. England was to be divided between the two kings, with Edmund keeping the vast Saxon heartland of Wessex and Cnut ruling over the kingdoms of Northumbria and Mercia in the north and east. Just weeks later, however, Edmund too died suddenly and Cnut ascended to the throne unopposed as England’s third king in just eight months. Historians today are divided over whether foul play was responsible for Edmund’s death, and while some sources claim he succumbed to infected wounds inflicted in battle, at least one much more vivid account claims he was stabbed up the backside, while sitting on a latrine, by an assassin hiding in a cesspit.

3. FRANCE, 1316

Louis XHulton Archive/Getty

When Louis X of France died on June 5, 1316 (either of pleurisy or from drinking poisoned wine, depending on which version you believe), a problem emerged over who should succeed him. Although Louis had a daughter, Joan, from his disastrous first marriage, a male heir was required—but Louis’s second wife, Queen Clementia of Hungary, was still pregnant at the time of the king’s death, and with the sex of the child unknown, it was impossible to tell whether Louis had a male successor or not.

As a result, Louis’s younger brother Philip was appointed regent for the final five months of the queen’s pregnancy, until finally, on November 15, 1316, she gave birth to a baby boy. The child was immediately crowned King John I, but died just five days later. The cause of his death is a mystery, and rumors soon emerged that the young king had likely been killed or exiled. But whatever the truth, Louis’s brother Philip was able to retake to the throne in his own right as King Philip V, becoming France’s third king in just six months.

4. THE VATICAN, 1590

Pope Sixtus VHulton Archive/Getty Images

After the death of Pope Sixtus V on August 27, 1590, Urban VII was elected to succeed him a little over two weeks later, on September 15. But by September 27, Urban VII, too, was dead. His 13-day papacy remains the shortest in history, but despite its brevity he is nevertheless credited with introducing one of the world’s first smoking bans, threatening anyone who “took tobacco in the porchway of or inside of a church” with immediate excommunication. After Urban’s death, Gregory XIV became pope—the third in just 100 days—on December 5, but he fared little better and died of a “gallstone attack” the following October.

5. RUSSIA, 1605

When Tsar Feodor I died without a male heir to succeed him in 1598, the Russian parliament elected his brother-in-law and former advisor, Boris Godunov, as his successor. Although the first few years of Boris’s reign were prosperous, his rule later became a disaster: Russia was devastated by a widespread famine that killed a third of the population, and Boris’s ever-weakening leadership saw the country soon descend into anarchy. On his death in April 1605, Boris’s 16-year-old son succeeded him as Tsar Feodor II, but his reign only lasted a few weeks as both he and his mother were assassinated. And that paved the way for a successor few people saw coming.

A few years earlier, in 1601, a young man living in Moscow had attracted considerable attention by asserting that he was Tsarevich Dmitri Ivanovich, the youngest son of Ivan the Terrible. Tsarevich Dmitri, it was believed, had either been killed or had died in a terrible accident at the age of just 8 in 1591. This Muscovite Dmitri, however, claimed that the stories of his death had been greatly exaggerated: He had supposedly managed to escape and flee into exile, and with Russia on the verge of anarchy, he had now returned to take his rightful place as tsar.

Threatened with banishment for his treasonable actions, Dmitri fled to Lithuania, but there began forging support for his cause. With the Polish-Lithuanian Commonwealth, Catholic groups, and an army of mercenaries from across continental Europe now behind him, Dmitri marched on Moscow and swept to power on Feodor’s death to become Russia’s third tsar in as many months.

But even “False” Dmitri, as he became known, wasn’t to hold the throne for too long. A little under a year later, the Kremlin was stormed and Dmitri was killed by his opponents, having broken his leg fleeing from an upstairs window. (According to popular legend, as one final gesture, his body was cremated and his ashes fired from a cannon pointed in the direction of Poland.)

Dmitri was succeeded by Prince Vasili Shuisky (one of the opponents who had plotted his downfall), who became Tsar Vasili IV on May 19, 1606. His reign wasn’t exactly lacking in drama either—two more “False Dmitris” emerged over the coming years—leading to this entire shambolic period of Russian history becoming known as “The Time of Troubles.”

6. GREAT BRITAIN, 1782

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It's generally agreed that on March 20, 1782, Lord North became the first Prime Minister in British history to resign, following a vote of no confidence. His 12-year term had seen him lead Britain through much of the American Revolutionary War, but the American victory at Yorktown in October 1781 had damaged his standing beyond repair and he was forced from power. His successor, the Marquess of Rockingham, was appointed a week later and quickly sought to negotiate a peaceful end to the war and to recognize America’s independence. Negotiations began in Paris in April—but were halted when Rockingham died suddenly during a flu epidemic after just 14 weeks in power.

In his place, King George III himself appointed Rockingham’s Secretary of State, William Petty, the Earl of Shelburne, as Britain’s third Prime Minister in just five months.