February 13

Mongol forces under Hulegu Khan sack and plunder Baghdad following the city's surrender, killing a large portion of its population and destroying its famed libraries.

Following the city's surrender, Mongol forces spent days massacring residents and destroying Baghdad's mosques, palaces, and legendary House of Wisdom library, whose vast collection of manuscripts was reportedly dumped into the Tigris River. The sack effectively ended the Abbasid Caliphate's five centuries of rule and is often cited as a devastating blow to the broader Islamic Golden Age.

Mongol forces under Hulegu Khan capture and sack Baghdad, bringing an end to the five-century-old Abbasid Caliphate.

The Mongol army breached the city's walls after a short siege, executing the last Abbasid caliph and massacring much of the population. The House of Wisdom, one of the era's great centers of learning, was destroyed and its library scattered into the Tigris. The fall of Baghdad marked the effective end of the Abbasid Caliphate and reshaped the political map of the Middle East for centuries to come.

England and the Lord of the Isles conclude the Treaty of Westminster-Ardtornish, in which John of Islay pledges allegiance to Edward IV of England in exchange for English support against the Scottish crown.

Signed secretly, the treaty saw John of Islay, Lord of the Isles, and the exiled Earl of Douglas agree to become vassals of the English crown and to help conquer and partition Scotland between them, with Edward IV providing an annual subsidy. The plot was never fully carried out, but when it came to light years later it was used as justification for forfeiting the Lordship of the Isles to the Scottish crown in 1493.

Catherine Howard, the fifth wife of Henry VIII, is executed for adultery, following the same fate as Anne Boleyn six years earlier.

Catherine Howard, a teenage cousin of Anne Boleyn, was accused of adultery and treason after evidence emerged of relationships before and possibly during her marriage to the aging Henry VIII. Her execution, following the same procedure used against Anne Boleyn, underscored the perilous position of Henry's wives.

Catherine Howard, the fifth wife of King Henry VIII of England, is executed at the Tower of London for adultery.

Catherine had married Henry VIII in 1540 when she was a teenager and he was in his late forties, but was later accused of having taken lovers, including the courtier Thomas Culpeper, while queen. Parliament passed an act of attainder condemning her without trial, and she was beheaded on Tower Green just eighteen months after her wedding, meeting the same fate as Henry's second wife, Anne Boleyn.

The Clergy Act comes into force in England, barring bishops from sitting in the House of Lords.

Passed by the Long Parliament amid growing conflict between Charles I and Parliament, the act reflected hostility toward the political power of the episcopacy and was one of several measures that deepened the rift leading to the English Civil War. Bishops had sat in the Lords for centuries as one of the estates of the realm; the exclusion was not reversed until the Restoration in 1661.

William III and Mary II are proclaimed joint monarchs of England following the Glorious Revolution that deposed James II.

William and Mary's joint rule followed the largely bloodless Glorious Revolution, in which Parliament invited the Dutch prince William to invade and depose the unpopular Catholic King James II. Their acceptance of a Bill of Rights limiting royal power marked a pivotal shift toward constitutional monarchy in England.

William III and Mary II are proclaimed joint sovereigns of England, formalizing the outcome of the Glorious Revolution.

Parliament had invited the Dutch prince William of Orange and his wife Mary, daughter of the deposed James II, to take the throne after James fled England in 1688. Their joint accession, agreed alongside the Bill of Rights, established firm limits on royal power and parliamentary supremacy that shaped the modern British constitutional monarchy.

Government soldiers massacre members of Clan MacDonald at Glencoe, Scotland, an act of betrayal that became a lasting symbol of Highland grievance.

Government soldiers who had been given hospitality by the MacDonald clan for nearly two weeks turned on their hosts under secret orders, killing dozens in their beds in a notorious breach of the traditional Highland code of hospitality. The massacre remains a potent symbol of clan grievance and government treachery in Scottish memory.

Members of Clan Campbell, acting on government orders, kill dozens of Clan MacDonald of Glencoe in the Massacre of Glencoe, after the MacDonalds were judged to have sworn allegiance to William III too late.

Government soldiers had lodged with the MacDonalds for nearly two weeks under the guise of hospitality before turning on their hosts at dawn, killing men, women, and children in their beds or as they fled into the snow-covered hills, where more later died of exposure. Ordered by the Scottish Secretary of State John Dalrymple, the massacre became a lasting symbol of betrayal and government overreach in the Scottish Highlands.

The 13th Dalai Lama proclaims Tibetan independence following the collapse of Qing dynasty authority over the region.

The young Dalai Lama's declaration came as Qing dynasty authority in China collapsed amid revolution, allowing Tibet to function with de facto independence for the following decades. The territory's political status remained contested internationally, and Chinese forces reasserted control in 1950.

New Delhi is formally inaugurated as the capital of British India, replacing Calcutta, in a ceremony presided over by the Viceroy, Lord Irwin.

The decision to move the seat of British Indian government from Calcutta to Delhi had been announced two decades earlier, in 1911, partly to distance the administration from unrest in Bengal and to evoke Delhi's history as an imperial capital. The new city, designed largely by British architects Edwin Lutyens and Herbert Baker, took nearly twenty years to build and remained the seat of government after Indian independence in 1947.

The Siege of Budapest ends with the unconditional surrender of German and Hungarian forces to the Red Army after a brutal two-month battle.

The prolonged Siege of Budapest, one of the most destructive urban battles of World War II, devastated the Hungarian capital and its historic bridges and buildings. Soviet forces suffered massive casualties capturing the city, which became an important staging ground for the final push into Germany and Austria.

British and American bombers begin a devastating firebombing campaign against Dresden, Germany, killing thousands and destroying much of the historic city.

The controversial firebombing of Dresden, a city with limited military-industrial significance, used incendiary bombs to create a massive firestorm that killed an estimated 25,000 civilians in a matter of days. It remains one of the most debated Allied actions of the war regarding the ethics of targeting civilian population centers.

The Siege of Budapest ends as the remaining German and Hungarian garrison surrenders to the Soviet Red Army.

The seven-week siege had trapped tens of thousands of Axis troops and civilians inside the Hungarian capital as Soviet and Romanian forces encircled the city. Fighting was fierce and block-by-block, leveling much of Buda's historic castle district, and the siege ranks among the costliest urban battles of the Second World War, with heavy losses on both sides and among trapped civilians.

Royal Air Force bombers begin a heavy night raid on the German city of Dresden, igniting a firestorm that continued with further American daylight raids over the following days.

Hundreds of RAF Lancaster bombers dropped incendiaries and high explosives on Dresden in two waves, creating a firestorm that destroyed much of the historic city center. The raid, undertaken as Soviet forces advanced from the east, became one of the most controversial Allied bombing operations of the war, with the scale of civilian casualties still debated by historians decades later.

France conducts its first nuclear weapons test in the Algerian desert, becoming the world's fourth nuclear power.

France's "Gerboise Bleue" test, conducted in the Algerian Sahara despite the ongoing Algerian War of Independence, made it the world's fourth nuclear power after the United States, Soviet Union, and Britain. The test cemented France's independent nuclear deterrent, a policy it maintained throughout the Cold War outside NATO's integrated command.

France detonates its first nuclear weapon, codenamed Gerboise Bleue, in the Sahara desert, becoming the world's fourth nuclear power.

The test took place near Reggane in French Algeria and yielded several times the explosive force of the bomb dropped on Hiroshima. It fulfilled a program pursued since the early 1950s under successive French governments determined to secure an independent nuclear deterrent, and it came as Algeria's push for independence intensified, later complicating France's continued use of the Saharan test sites.

Coalition smart bombs destroy the Amiriyah shelter in Baghdad during the Gulf War, killing over 400 Iraqi civilians sheltering inside.

U.S. forces had targeted the Amiriyah facility believing it was a military command bunker, unaware that hundreds of civilians were sheltering inside from ongoing airstrikes. The devastating civilian toll became one of the most controversial incidents of the Gulf War and a rallying point for anti-war criticism.

Kim Jong-nam, the estranged half-brother of North Korean leader Kim Jong-un, is assassinated with a nerve agent at a Malaysian airport.

Kim Jong-nam, once considered a potential heir to North Korea's leadership before falling out of favor, was killed with VX nerve agent by two women in a Kuala Lumpur airport who later claimed they believed they were participating in a prank for a hidden-camera show. The brazen assassination drew international condemnation and strained Malaysia-North Korea relations.