September 20

Norwegian King Harald Hardrada defeats English earls at the Battle of Fulford.

Norwegian King Harald Hardrada, invading northern England alongside the rebellious Earl Tostig, defeated the combined forces of English earls Edwin and Morcar near York, a victory that briefly opened the north to Norwegian control before Harald's defeat and death at Stamford Bridge days later.

Saladin launches his military campaign to retake Jerusalem from Crusader control.

Having consolidated his power in Egypt and Syria, the Muslim leader Saladin launched a determined military campaign to retake Jerusalem from Crusader control, a siege that succeeded within weeks and dealt a severe blow to Crusader holdings in the Levant.

Cardinal Robert of Geneva becomes the rival Pope Clement VII, beginning the Western Schism within the Catholic Church.

Amid disputed papal elections following the death of Pope Gregory XI, Cardinal Robert of Geneva was elected as a rival pope taking the name Clement VII, establishing a parallel papacy based in Avignon that created decades of division within the Catholic Church known as the Western Schism.

A tsunami destroys the hall housing the Great Buddha statue at Kotoku-in in Japan, leaving the bronze statue exposed to the elements ever since.

A massive tsunami, likely triggered by a distant earthquake, swept inland and destroyed the wooden hall that had sheltered Japan's Great Buddha statue at Kotoku-in for centuries, leaving the enormous bronze figure permanently exposed to the open air, as it remains to this day.

Ferdinand Magellan departs on the expedition that ultimately achieves the first circumnavigation of the globe.

Portuguese navigator Ferdinand Magellan departed Spain with a fleet of five ships under Spanish sponsorship, embarking on the expedition that would achieve the first circumnavigation of the globe, though Magellan himself died in the Philippines before the voyage's completion. Only one battered ship and a small fraction of the original roughly 270-man crew ultimately returned to Spain three years later.

Conspirators in the Babington Plot to assassinate Queen Elizabeth I are executed.

Fourteen conspirators implicated in a plot to assassinate Queen Elizabeth I and place the imprisoned Mary, Queen of Scots on the English throne were executed, a plot whose discovery ultimately sealed Mary's own fate as well, leading to her execution the following year.

The Treaty of Ryswick is signed, ending the Nine Years' War in Europe.

European powers signed the Treaty of Ryswick, concluding the costly Nine Years' War fought largely to contain the territorial ambitions of France's King Louis XIV against a broad coalition of rival European states. The negotiated settlement restored most conquered territories to their prewar rulers, offering only a temporary respite before renewed continental conflict erupted again within a few years.

French revolutionary forces achieve a decisive victory at the Battle of Valmy, halting the Prussian invasion.

French revolutionary forces, bolstered by patriotic fervor and effective artillery, halted an invading Prussian army at Valmy, an unexpected victory that saved the fledgling French Republic and is often credited with securing the revolution's survival in its earliest and most vulnerable phase.

Italian unification is completed as troops enter Rome, ending the Papal States' temporal rule.

Italian troops breached the walls of Rome and entered the city, completing the long process of Italian unification by ending the Pope's centuries-long temporal rule over the city, which was then incorporated as the new capital of the Kingdom of Italy.

Chester A. Arthur is sworn in as U.S. president following the death of James Garfield.

Following the assassination of President James Garfield, Vice President Chester A. Arthur was sworn in as his successor at his New York City home in a modest late-night ceremony. Arthur went on to surprise many critics by championing civil service reform despite his earlier reputation as a product of the political patronage system he later helped dismantle.