April 16

The Revolt of the Comuneros begins in Spain, a rebellion against the rule of the young King Charles V.

A widespread popular uprising known as the Revolt of the Comuneros erupted across cities in central Spain, driven by opposition to the policies of the young, foreign-born King Charles V, who had recently inherited the Spanish throne. Royalist forces eventually crushed the rebellion the following year, reinforcing centralized royal authority over Spain's traditionally independent-minded municipalities.

British Hanoverian forces crush the Jacobite rising at the Battle of Culloden in Scotland, ending Stuart hopes of reclaiming the throne.

British Hanoverian government forces decisively crushed the Jacobite army loyal to Charles Edward Stuart, known as "Bonnie Prince Charlie," at the Battle of Culloden in the Scottish Highlands, ending the last major attempt to restore the Stuart dynasty to the British throne. The brutal aftermath included harsh suppression of Highland culture and clan traditions.

Harriet Quimby becomes the first woman to pilot an airplane across the English Channel.

American aviator Harriet Quimby became the first woman to pilot an airplane across the English Channel, flying from England to France in a flimsy Blériot monoplane despite thick fog that obscured her view for much of the flight. Her achievement was largely overshadowed in the press by the sinking of the Titanic just days earlier.

Vladimir Lenin returns to Russia from exile in Switzerland, setting the stage for the Bolshevik Revolution later that year.

Revolutionary leader Vladimir Lenin returned to Russia from exile in Switzerland aboard a German-arranged sealed train, arriving at Petrograd's Finland Station to a large crowd of supporters. His return, facilitated by Germany in hopes of destabilizing Russia's war effort, set the stage for the Bolshevik seizure of power later that year.

Swiss chemist Albert Hofmann accidentally discovers the hallucinogenic effects of LSD.

Swiss chemist Albert Hofmann accidentally absorbed a small amount of a compound he had synthesized years earlier while researching potential medicinal uses, discovering its powerful hallucinogenic effects during an unplanned and disorienting bicycle ride home. His discovery of LSD's psychoactive properties would go on to have a profound and controversial influence on science, medicine, and 1960s counterculture.

The Red Army launches its final assault on Berlin with nearly one million troops, beginning the last major battle of the European war.

Soviet forces under Marshal Georgy Zhukov launched the massive Battle of Berlin, deploying nearly one million troops and thousands of tanks and artillery pieces against the crumbling German capital. The brutal, weeks-long battle would result in Adolf Hitler's suicide and Germany's unconditional surrender within weeks, marking the definitive end of the war in Europe.

A massive explosion aboard a fertilizer-laden freighter in Texas City, Texas, triggers a chain reaction of fires and blasts that kill roughly 600 people.

A fire aboard a French-owned freighter loaded with ammonium nitrate fertilizer docked in Texas City, Texas, triggered a massive explosion that ignited nearby chemical plants and oil facilities, killing roughly 600 people in what remains one of the deadliest industrial accidents in American history. The disaster led to significant reforms in the regulation and handling of hazardous chemicals.

Fidel Castro publicly declares the Cuban Revolution socialist for the first time, aligning Cuba with the Soviet bloc.

In a nationally broadcast speech, Cuban leader Fidel Castro publicly declared for the first time that the Cuban Revolution was socialist, formally aligning the island nation with the Soviet Union just as a CIA-backed invasion force prepared to land at the Bay of Pigs. The declaration marked a decisive turning point in Cuba's Cold War allegiance.

A gunman kills 32 people in the deadliest mass shooting on a U.S. college campus at Virginia Tech.

A student gunman killed 32 people and wounded 17 others in two separate attacks on the Virginia Tech campus before taking his own life, in what was then the deadliest mass shooting by a single gunman in modern U.S. history. The tragedy prompted widespread debate over campus security, mental health services, and gun control policy.

The South Korean ferry MV Sewol capsizes and sinks, killing 304 passengers and crew, most of them students.

The South Korean ferry MV Sewol capsized and sank off the country's southwestern coast, killing 304 people, most of them high school students on a field trip, after the overloaded and improperly secured vessel made a sharp turn. The disaster, compounded by a botched rescue response, triggered nationwide grief and outrage and led to significant reforms of South Korea's maritime safety regulations.