August 27

The Visigothic sack of Rome, led by King Alaric I, concludes after three days of pillaging.

After breaching Rome's walls days earlier, Visigothic forces under King Alaric I concluded their sack of the city, having plundered its wealth over three days, an event that sent shockwaves throughout the Roman world as the first foreign capture of the city in centuries.

Henry the Young King and Margaret of France are crowned as junior monarchs of England.

Henry, the eldest surviving son of King Henry II of England, was crowned as a junior co-king alongside his father in a controversial arrangement intended to secure succession, though the younger Henry's frustration with his limited actual authority later contributed to a significant family rebellion.

Henry the Young King and his wife Margaret of France were crowned together at Winchester, cementing his status as junior king of England.

Henry II's eldest surviving son had already been crowned king in 1170, but that ceremony had excluded his wife, provoking anger from her father, Louis VII of France. This second coronation was intended to smooth over the diplomatic insult, though it did nothing to resolve the deeper tensions between the Young King and his father, which erupted into open rebellion less than a year later.

A combined Aragonese-Venetian fleet decisively defeats the Genoese navy at the Battle of Alghero.

A combined fleet from the maritime republics of Aragon and Venice decisively defeated the naval forces of rival Genoa near Alghero on the island of Sardinia, contributing to the broader struggle for Mediterranean commercial dominance among Italy's competing maritime powers.

Emmanuel Philibert secures his position as Duke of Savoy through military victory.

Following military conflict with rivals seeking to seize control of his territory, Emmanuel Philibert successfully secured and consolidated his hereditary claim to the Duchy of Savoy, later relocating the Savoyard capital from Chambery to Turin and beginning significant modernization of the state's administration, legal code, and military organization that strengthened Savoy's regional standing.

British forces under General William Howe outflank and defeat the Continental Army at the Battle of Long Island.

British forces under General William Howe executed a successful flanking maneuver against General George Washington's Continental Army positions on Long Island, forcing a costly American retreat that nearly resulted in the destruction of Washington's entire army early in the Revolutionary War.

British forces under General William Howe defeated George Washington's Continental Army at the Battle of Long Island.

In the largest battle of the American Revolutionary War, Howe's troops outflanked and routed the poorly prepared Continental Army in Brooklyn, inflicting heavy casualties and capturing hundreds of prisoners. Only a skilful nighttime evacuation across the East River saved Washington's remaining forces from destruction, allowing the war to continue despite this early, decisive British victory.

Royalist rebels at Toulon opened the port to British and Spanish fleets, prompting a lengthy siege by revolutionary French forces.

Fearful of the radical Jacobin government in Paris, the citizens of Toulon invited an Anglo-Spanish fleet under Admiral Samuel Hood to occupy the strategic naval base. The subsequent siege by Republican forces became famous for the role of a young artillery officer, Napoleon Bonaparte, whose tactics helped force the British and their allies to evacuate the city that December.

French and Irish rebel forces routed British Crown troops at the Battle of Castlebar during the Irish Rebellion of 1798.

A small French expeditionary force under General Jean Humbert, joined by Irish United Irishmen, put a much larger British and militia garrison to flight in County Mayo. The rapid, humiliating retreat became known as the 'Castlebar Races.' The rebels briefly held the town before British reinforcements crushed the rebellion in the weeks that followed.

The French Navy inflicted a rare defeat on the British Royal Navy at the Battle of Grand Port off Mauritius.

French frigates trapped and destroyed or captured four British warships in the shallow, reef-strewn harbour of Grand Port, the only French naval victory ever inscribed on the Arc de Triomphe. Despite the loss, Britain went on to seize Mauritius from France just months later, ending French naval power in the Indian Ocean for the remainder of the Napoleonic Wars.

Petroleum is discovered near Titusville, Pennsylvania, launching the modern commercial oil industry.

Edwin Drake's successful drilling operation near Titusville, Pennsylvania, struck oil at a shallow depth of roughly 69 feet using a pioneering drilling technique adapted from salt-well boring methods, launching the modern commercial petroleum industry. The subsequent regional oil boom transformed American energy production and rapidly established Pennsylvania as the birthplace of the global oil age.

A series of massive volcanic explosions nearly destroys the island of Krakatoa, generating tsunamis that kill tens of thousands.

A series of massive volcanic explosions tore apart most of the Indonesian island of Krakatoa, generating an eruption heard thousands of miles away and devastating tsunamis that killed tens of thousands of people across the surrounding coastal regions of Java and Sumatra.

The Anglo-Zanzibar War, the shortest recorded war in history, concludes in under an hour.

Following a diplomatic dispute over succession to the Zanzibari throne after the death of a British-favored sultan, Royal Navy warships bombarded the sultan's palace, destroying it within approximately 38 minutes and forcing the rival claimant's surrender, making the Anglo-Zanzibar War the shortest recorded war in documented military history.

Britain and the Sultanate of Zanzibar fought the shortest war in recorded history, lasting under 40 minutes.

After Sultan Khalid bin Barghash seized power without British approval, the Royal Navy bombarded his palace, and the fighting ended in roughly 38 minutes with Khalid fleeing and several hundred Zanzibari casualties. British forces then installed a more compliant sultan, tightening their control over the island as part of the wider scramble for influence in East Africa.

The Royal Munster Fusiliers fought a costly delaying action against advancing German forces at the Battle of Étreux.

During the British Expeditionary Force's retreat from Mons, the battalion held off a much larger German force for most of the day near the French village of Étreux, buying time for other British units to withdraw. Nearly the entire battalion was killed, wounded, or captured, and the stand became one of the notable early sacrifices of the British Army in the First World War.

The world's first jet-powered aircraft, the Heinkel He 178, completes its maiden flight in Germany.

Germany's Heinkel He 178, powered by a revolutionary turbojet engine developed by engineer Hans von Ohain, completed the world's first flight of a jet-propelled aircraft, though the technology's true military and commercial potential would not be fully realized for several more years.

The first edition of the Guinness Book of Records was published in Britain.

Commissioned by Guinness Brewery managing director Sir Hugh Beaver after a dispute over the fastest game bird in Europe, the reference book compiled by twin researchers Norris and Ross McWhirter became an instant bestseller. It grew into an annually updated global phenomenon, now known simply as Guinness World Records, cataloguing extremes of every kind.

Calder Hall in Cumbria, England, became the world's first nuclear power station to supply electricity commercially on a large scale.

Opened by Queen Elizabeth II, the plant fed power into the national grid, marking a milestone in the peaceful use of nuclear energy after its wartime origins in weapons research. Though later criticised for also producing plutonium for Britain's nuclear arsenal, Calder Hall operated for nearly half a century and helped establish Britain as a pioneer of civil nuclear power.

The IRA killed 18 British soldiers in a bomb ambush at Warrenpoint and assassinated Lord Mountbatten in a separate bombing the same day.

The Warrenpoint ambush, using two roadside bombs in quick succession, was the deadliest single attack on the British Army during the Troubles. Hours earlier, a bomb hidden aboard Lord Mountbatten's boat off Mullaghmore, County Sligo, killed the former Viceroy of India and three others, including his 14-year-old grandson, in one of the IRA's most high-profile assassinations.

Hurricane Irene strikes the U.S. East Coast, causing approximately $15.6 billion in damages.

Hurricane Irene made landfall along the U.S. East Coast, causing widespread flooding and significant wind damage across a dozen states stretching from North Carolina to New England, resulting in approximately $15.6 billion in total damage and dozens of storm-related deaths, prompting one of the largest coastal evacuations in American history at the time.