April 6

Julius Caesar defeats the last significant Pompeian resistance at the Battle of Thapsus in North Africa.

Julius Caesar decisively defeated the combined forces of Metellus Scipio and Numidian King Juba I at the Battle of Thapsus in North Africa, effectively crushing the last major military resistance of the Optimates faction that had opposed him in Rome's civil war. Cato the Younger, a prominent opponent unwilling to accept defeat or Caesar's clemency, took his own life shortly after learning of the outcome.

Scottish nobles reaffirm the country's independence in the Declaration of Arbroath.

Scottish nobles and clergy sent a letter to Pope John XXII known as the Declaration of Arbroath, forcefully asserting Scotland's independence from England and defending King Robert the Bruce's authority to rule. The document's eloquent statement that Scots would fight not for glory or wealth but "for freedom alone" has made it one of the most celebrated texts in Scottish history.

Ottoman forces under Sultan Mehmed II begin the siege of Constantinople, which would fall weeks later, ending the Byzantine Empire.

Ottoman Sultan Mehmed II positioned his massive army, including powerful new siege cannons, outside the walls of Constantinople, beginning a siege that would last nearly two months. The city's eventual fall on May 29 ended the roughly thousand-year-old Byzantine Empire and gave the Ottomans control of a strategically vital crossroads between Europe and Asia, reshaping the region's political and religious landscape.

Dutch official Jan van Riebeeck establishes a resupply station at the Cape of Good Hope, the seed of what became Cape Town.

Dutch East India Company official Jan van Riebeeck landed at the Cape of Good Hope and established a small resupply station intended to provision company ships traveling between Europe and Asia. The settlement grew over subsequent decades into Cape Town, becoming the foundation of permanent European colonization in southern Africa, with lasting and often deeply contested consequences for the region's indigenous peoples.

Joseph Smith formally organizes the Church of Christ, the original name of what became the Latter Day Saint movement.

Joseph Smith and a small group of followers formally organized the Church of Christ in Fayette, New York, based on the Book of Mormon, which Smith said he had translated from golden plates revealed to him. The church, later renamed The Church of Jesus Christ of Latter-day Saints, grew despite intense persecution into one of the largest homegrown American religious movements.

The first modern Olympic Games open in Athens, Greece, reviving a tradition dormant since antiquity.

The first modern Olympic Games opened in Athens, Greece, reviving a tradition of athletic competition rooted in ancient Greek festivals that had been dormant for over 1,500 years. Organized largely through the efforts of French educator Pierre de Coubertin, the games drew roughly 250 athletes from 14 nations and established the foundation for what became the world's largest international sporting event.

The United States formally declares war on Germany, entering World War I.

Congress formally declared war on Germany after President Woodrow Wilson's request days earlier, officially bringing the United States into World War I on the side of the Allied powers. American troops and industrial capacity, though slow to fully mobilize, ultimately provided a decisive boost that helped tip the exhausted conflict in the Allies' favor by the following year.

Yugoslav Partisans liberate Sarajevo from Axis occupation.

Yugoslav Partisan forces under Josip Broz Tito liberated the city of Sarajevo from Axis occupation after years of brutal fighting during World War II, part of the broader Partisan campaign that eventually drove German and collaborationist forces from Yugoslav territory. The liberation came at enormous cost, with Yugoslavia suffering some of the highest per-capita casualties of any country during the war.

ABBA wins the Eurovision Song Contest with "Waterloo," launching the group to international stardom and securing Sweden's first Eurovision win.

Swedish pop group ABBA won the Eurovision Song Contest with their breakout single "Waterloo," a victory that launched the group to international stardom and gave Sweden its first Eurovision win. The song's catchy, upbeat sound and the group's subsequent string of global hits helped make ABBA one of the best-selling music acts in history.

A magnitude 6.3 earthquake strikes near L'Aquila, Italy, killing over 300 people.

A magnitude 6.3 earthquake struck the central Italian city of L'Aquila and surrounding villages in the middle of the night, killing over 300 people and leaving tens of thousands homeless. The disaster later became the center of a controversial criminal trial in which several Italian scientists were initially convicted, and later acquitted, of manslaughter for allegedly downplaying earthquake risk in public statements before the quake.