On October 25

At 49 days, Liz Truss concluded the shortest tenure as prime minister of the United Kingdom.

Mount Merapi in Central Java, Indonesia, began an increasingly violent series of eruptions that lasted over a month.

Windows XP, one of the most popular and widely used versions of the Microsoft Windows operating system, was released for retail sale.

The People's Volunteer Army ambushed the South Korean II Corps at the Battle of Onjong, and elsewhere engaged the 1st Infantry Division at the Battle of Unsan, marking China's entry into the Korean War.

USS Tang, the U.S. Navy submarine credited with sinking more ships than any other American submarine, sank when it was struck by its own torpedo.

Heinrich Himmler ordered a crackdown on the Edelweiss Pirates, a nonconformist youth group that assisted army deserters and others hiding from the Nazis.

The Italian cruise liner SS Principessa Mafalda sank when a propeller shaft broke and fractured the hull, resulting in 314 deaths.

The Daily Mail published the Zinoviev letter, a hoax purported to be a directive from Moscow to increase communist agitation.

Irish playwright and politician Terence MacSwiney died after a hunger strike in Brixton Prison, bringing the Irish struggle for independence to international attention.

American Civil War: During Price's Missouri Expedition, Union troops defeated Sterling Price's Confederate army in three successive battles: Marais des Cygnes, Mine Creek, and Marmiton River.

Crimean War: The ill-fated Charge of the Light Brigade was decisively repelled by Russian forces during the Battle of Balaclava.

George III became King of Great Britain and Ireland, succeeding his grandfather George II.

Dutch explorer Dirk Hartog left a plate on an island in Shark Bay, the oldest-known artefact of European exploration in Australia still in existence.

Hundred Years' War: The army of Henry V of England, consisting mostly of archers, unexpectedly defeated the numerically superior French cavalry at the Battle of Agincourt (pictured) on Saint Crispin's Day.

Reconquista: Forces under Afonso I of Portugal captured Lisbon from the Moors after a four-month siege (depicted) in one of the few Christian victories during the Second Crusade.