January 25

Abbasid forces defeat the Umayyad Caliphate at the Battle of the Zab, ending Umayyad rule and beginning the Abbasid Caliphate.

The Abbasid victory at the Zab river, aided by superior tactics and disillusionment among Umayyad troops, ended the Umayyad dynasty's near century-long rule over the Islamic caliphate. The Abbasids soon moved the caliphate's capital to the newly founded city of Baghdad, ushering in an era often remembered as the Islamic Golden Age of science, philosophy, and culture.

Edward III ascends the throne of England at age fourteen after his father is forced to abdicate.

Edward III's father, Edward II, had been forced to abdicate amid political turmoil and was likely murdered in captivity shortly afterward. The young king initially ruled under the regency of his mother, Isabella, and her lover Roger Mortimer, before seizing personal control at 17 and going on to launch the Hundred Years' War with France.

King Henry VIII of England secretly marries his second wife, Anne Boleyn.

Henry VIII's secret marriage to Anne Boleyn, conducted before his first marriage to Catherine of Aragon had been formally annulled, was a decisive step in his break from the Catholic Church, since the pope refused to grant the annulment. The resulting split led to the establishment of the Church of England, with Henry as its head, one of the most consequential religious ruptures in English history.

The first Winter Olympic Games open in Chamonix, France.

The inaugural Winter Games in the French Alpine town of Chamonix featured events like figure skating, ice hockey, and bobsled, though it wasn't officially designated the "first Winter Olympics" until after the fact, since it was initially held as an International Winter Sports Week. Its success led the International Olympic Committee to establish separate, recurring Winter Games from then on.

The Battle of the Bulge, the last major German offensive on the Western Front, ends in Allied victory.

German forces launched their last major offensive of World War II through the densely forested Ardennes region, aiming to split Allied lines and retake the port of Antwerp. American forces, notably at the besieged town of Bastogne, held out against fierce winter fighting and heavy casualties, and the battle's failure critically depleted Germany's remaining reserves ahead of the final Allied push into Germany.

Blue Ribbon Sports, later renamed Nike, is founded by University of Oregon athletes.

Phil Knight and his former college track coach Bill Bowerman founded the company to import and sell Japanese running shoes, initially selling them out of the back of a car at track meets. The company was renamed Nike in 1971 after the Greek goddess of victory and grew into one of the largest and most influential athletic apparel companies in the world.

Charles Manson and four members of his "Family" are found guilty of the 1969 Tate–LaBianca murders.

Manson, who never personally committed the murders himself, was convicted of orchestrating them through his cult-like "Family" of followers, who killed actress Sharon Tate and several others in a plot he believed would ignite a race war. The sensational trial captivated national attention and made Manson one of the most notorious criminal figures in American history.

Russia nearly launches a nuclear counterattack after mistaking a Norwegian scientific rocket for an incoming missile.

A Norwegian scientific rocket, launched to study the aurora borealis, closely resembled the flight profile of a U.S. submarine-launched ballistic missile, triggering Russia's nuclear alert system and reportedly reaching President Boris Yeltsin, who had the launch codes ready before the rocket was identified as harmless. The incident remains one of the closest known calls to accidental nuclear war since the Cuban Missile Crisis.

Mass demonstrations in Cairo mark the start of the Egyptian revolution.

Mass protests erupted across Egypt against President Hosni Mubarak's nearly 30-year authoritarian rule, driven by grievances over corruption, unemployment, and police brutality, inspired partly by Tunisia's recent uprising. Sustained demonstrations centered on Cairo's Tahrir Square continued for over two weeks and ultimately forced Mubarak to resign, part of the broader wave of uprisings known as the Arab Spring.

A mining dam collapses in Brumadinho, Brazil, killing 270 people.

A dam holding mining waste from an iron ore operation collapsed suddenly, unleashing a massive wave of toxic mud that buried nearby company buildings and a cafeteria full of workers during their lunch break. The disaster, one of Brazil's worst industrial accidents, led to criminal charges against mining company executives and prompted stricter regulation of similar dams nationwide.