October 21 in Military History

Crusader forces arrived at the walls of Antioch, beginning one of the longest and most grueling sieges of the First Crusade. The siege would last nearly eight months before the Crusaders breached the city through treachery, only to find themselves immediately besieged in turn by a massive Muslim relief army. The ordeal at Antioch tested the Crusaders to their limits and became a defining episode of the medieval holy wars.

Tokugawa Ieyasu's eastern army defeated the western coalition under Ishida Mitsunari at the Battle of Sekigahara in central Japan, the largest and most decisive battle in Japanese feudal history. Approximately 160,000 samurai fought in the engagement, with betrayals by western generals proving decisive. The victory established the Tokugawa Shogunate, which would rule Japan for over 250 years.

Admiral Nelson's Royal Navy fleet destroyed the combined Franco-Spanish fleet off Cape Trafalgar. Nelson was killed but his victory shattered Napoleon's invasion plans and established British naval supremacy for a century.

Vice Admiral Horatio Nelson's 27 ships of the line destroyed the combined Franco-Spanish fleet of 33 ships under Vice Admiral Pierre-Charles Villeneuve off Cape Trafalgar in southern Spain. The victory, in which Nelson was killed by a French sharpshooter, ended Napoleon's hopes of invading Britain and established British naval supremacy that would last more than a century.

Soldiers of the U.S. 1st Division fired the first American artillery shell of World War I near the village of Bathélémont in the Lunéville sector of France. The event marked America's transition from a training force to an active combatant on the Western Front. The 1st Division, the "Big Red One", would go on to fight in every major American engagement of the war.

The destroyer USS Kearny was struck by a German U-568 torpedo while escorting Convoy SC-48 approximately 400 miles southwest of Iceland. Eleven American sailors were killed in the attack, the first U.S. Navy combat deaths of World War II, six weeks before the formal American declaration of war against Germany.

American carrier aircraft attacked the Japanese Center Force under Admiral Kurita in the Sibuyan Sea during the Battle of Leyte Gulf. Repeated air strikes sank the super-battleship Musashi, one of the two largest warships ever built, after absorbing an estimated 19 torpedo and 17 bomb hits. The action was part of history's largest naval battle, involving over 280 ships.

After three weeks of house-to-house fighting, American forces of VII Corps captured Aachen, the first major German city to fall to Allied forces in World War II. The battle had demonstrated the enormous cost of urban combat against prepared defenses, a lesson that would shape American infantry doctrine through the Cold War and beyond.

The first elements of the Chinese People's Volunteer Army under General Peng Dehuai crossed the Yalu River into North Korea, beginning the Chinese intervention in the Korean War. Within weeks, more than 300,000 Chinese soldiers would be engaged against United Nations forces, turning what had appeared to be an imminent UN victory into the longest war of American history to that point.

Approximately 100,000 anti-Vietnam War demonstrators gathered at the Lincoln Memorial in Washington, D.C., with 35,000 then marching to the Pentagon in one of the most dramatic confrontations between the anti-war movement and the military establishment. Protesters famously placed flowers in the barrels of soldiers' rifles, creating iconic images. Over 680 people were arrested in clashes that lasted through the night.