List of military disasters

A military disaster is the unexpected and sound defeat of one side in a battle or war, and often changes the course of history.

A military disaster can range from a strong army losing a major battle against a clearly inferior force, to an army being surprised and defeated by a clearly superior force, to a seemingly evenly matched conflict with an extremely one sided result. A military disaster could be due to bad planning, bad execution, bad weather, general lack of skill or ability, the failure of a new piece of military technology, a major blunder, a brilliant move on the part of the enemy, or simply the unexpected presence of an overwhelming enemy force.

Ancient era

 * The Battle of Salamis in 480 BC where a huge Persian fleet is defeated by a united Greek force.
 * The Athenian expedition to Syracuse in 415 BC.
 * The Battle of Cannae in 216 BC, where Hannibal destroyed the sixteen Roman and Allied legions, led by Lucius Aemilius Paullus and Gaius Terentius Varro. In all, perhaps more than 80% of the entire Roman army was dead or captured (including Paullus himself).
 * The Battle of Julu in 207 BC where Chu forces under Xiang Yu defeated a much larger Qin army. Qin's losses mounted to well over 100,000. The Qin dynasty collapsed soon after.
 * The Battle of Mobei in 119 BC, where the entire Xiongnu army of over 100,000 men was destroyed by the Han army. This battle and its aftermath ensured the supremacy of the Chinese over the northern barbarian tribes for the next few hundred years.
 * The Battle of Carrhae in 53 BC when Crassus with 40,000 soldiers marched into Parthia expecting to be victorious, chose to march a direct route through the desert instead of the mountains of the north, and was entirely anniliated by 9,000 Parthian soldiers
 * The Siege of Alesia in 52 BC, where Gaius Julius Caesar, leading roughly 50,000 Roman soldiers, laid siege to the rebel Gauls, led under Vercingetorix, fortress of Alesia, who numbered at roughly 85,000 infantry and 15,000 cavalry. The Belgae tribe attempted to relieve the siege with an army of 260,000 warriors. The Romans, through the personal leadership of Titus Labienus, wrought a terrific slaughter upon the Belgae, this demoralising event leading the defenders at Alesia to yield, ending Vercingetorix's rebellion.
 * The Battle of Teutoburg Forest in 9 AD, where German warriors destroyed three Roman legions
 * The Battle of Watling Street in 60 or 61 AD, where, Tacitus and Cassius Dio suggest, between 100,000 and 250,000 British warriors and tribes-people led by the British Iceni queen, Boudicca, faced off against 10,000 Roman soldiers led by the governor of the British province, Gaius Suetonius Paulinus. The result was an overwhelming annihilation of the Britons, upwards of 80,000 killed, with around 400 Romans dead, according to Tacitus. This ended the British rebellion that had devastated Roman-British provincial towns.
 * The Battle of Guandu in 200 AD, in which the more powerful army of Yuan Shao failed to guard its supplies, and was defeated by Cao Cao.
 * The Battle of Red Cliffs in 208 AD, where Liu Bei's advisor Zhuge Liang and Sun Quan's advisor Zhou Yu destroyed Cao Cao's much larger navy with fire.
 * The Battle of Edessa occurred in 259 AD when Emperor Valerian with a 70,000 strong Roman army marched into Persia to end Persian advances into Roman territory. The outcome was an overwhelming Persian victory and the entire Roman army was decimated.
 * The Battle of Adrianople in 378 AD, in which the emperor Valens was killed while Gothic heavy cavalry ambushed and decimated his Roman heavy infantry.

Medieval era

 * The Battle of Yarmuk in 636. The bulk of the Byzantine military along with their Christian Arab allies are destroyed.
 * The Battle of al-Qādisiyyah in 636 - The Arab Muslim army decisively defeated the larger Sassanid Persian army resulting in the Islamic conquest of Persia.
 * The Battle of Tours in 732. The Muslim Moors marched into France meeting no foes. The Moors met the Christian Frankish forces led by Charles Martel at Tours. Despite the Moorish advantage over the Franks militarily, they were defeated decisively by the Franks.
 * The Battle of Acheloos in 927. An enormous Byzantine army of 110,000 men was tactically outwitted by a smaller Bulgarian force, causing the death of 90,000 soldiers, 70,000 of whom were Byzantines in one of the bloodiest battles in the Middle Ages. The bones of tens of thousands who perished could be seen on the battlefield 75 years later.
 * The Battle of Hastings in 1066. The Anglo-Saxon King Harold is slain in battle with the Normans led by William the Conqueror, resulting in the Norman Conquest of England.
 * The Battle of Manzikert in 1071. The Byzantine Empire suffers a humiliating defeat at the hands of the Seljuks, resulting in the capture of Emperor Romanos IV.
 * The Battle of Hattin in 1187, where overconfident Crusader forces from Jerusalem became trapped in a waterless desert area, and thus became easy prey for the Saracen forces of Salah-ud-din (Saladin)
 * The Battle of Stirling Bridge in 1297. English Earl John de Warenne's well-equipped army were trapped on a narrow bridge by William Wallace's 15,000 unarmored, lightly armed Scots, bearing the traditional long spears of lowland Scotland. The bridge had been chosen as the point of engagement by Warenne, even though the river could easily have been forded just a few miles upstream.
 * The Battle of Nicopolis in 1396 was the rout of an allied army of Hungarian, Wallachian, French, Burgundian, German and assorted troops at the hands of an Ottoman force in modern-day Bulgaria. It is often referred to as the Crusade of Nicopolis and was the last large-scale crusade of the Middle Ages.
 * The Battle of Agincourt in 1415 - A large force of French knights were defeated by English longbowmen.
 * The Tumu Crisis in 1449-A very large force (500000) of the Ming dynasty were defeated by a very small army (20000) of Mongols and the Zhengtong Emperor of the Ming dynasty was captured. This battle is regarded as the greatest military debacle of the all chinese history. There is a legend that Zhengtong Emperor had been working as a herder during the capture in Mongol.

16th century

 * The Battle of Flodden Field in 1513 - A Scottish invasion of England is defeated, resulting in the death of the King James IV of Scotland
 * The First battle of Panipat in 1526 - Babur sacked Delhi and defeated Ibrahim Lodhi.
 * The Siege of Vienna in 1529 marked the height of the Ottoman Empire. Suleiman the Magnificent failed to capture the city, despite significant advantages in manpower.
 * The Battle of Lepanto in 1571. The Holy League's fleet defeated the Ottoman fleet in one of the largest naval battles of human history. The Ottomans lost 240 ships (out of about 300), while the League lost 12 of their 210 ships.
 * The Spanish Armada in 1588. An English fleet sends fire ships into the Spanish invasion fleet destroying some and scattering the rest effectively ending the invasion threat. The Armada would later run into storms and almost half the ships never returned to Spain, as well as more than half the troops.
 * The English Armada in 1589, where the English fleet was defeated by the recovering Spanish fleet. The allowed the Spanish fleet to quickly recover and maintained their shipping from the Americas.
 * The Battle of the Yellow Ford in 1598. An English force of 4000 is ambushed by Irish defenders under Hugh O'Neill and defeated. This temporarily put Ireland out of English control, allowing the rebellion to spread throughout Ireland.

17th century

 * The Battle of Saraighat in March 1671. The Ahoms under their general Lachit Borphukan defeated the Rajput general Ram Singh`s Mughal imperial forces consisting of 4,000 troopers (from his char-hazaari mansab), 1,500 ahadis and 500 barqandezes by an additional 30,000 infantrymen, 21 Rajput chiefs (Thakurs) with their contingents, 18,000 cavalry, 2,000 archers and shieldmen and 40 ships.

18th century

 * The Battle of Poltava in June 1709. Charles XII of Sweden's disastrous defeat ended his wintertime march on Moscow during the Great Northern War and marked the beginning of the end of the Swedish Empire.
 * The Battle of the Salween River in September 1718. An entire Qing army was destroyed by Zunghar Mongols.
 * The Battle of Cartagena de Indias in March–May of 1741. This battle, fought in the War of Jenkins' Ear, saw a huge British amphibious force of 26,400 men and 186 ships beat back and defeated by 4,000 Spanish troops and just 6 ships. The British pulled back after losing over 8,000 men killed, 7,500 wounded losing 1,500 guns and 50 ships.
 * The Battle of Saratoga in September-October 1777. John Burgoyne's British Army is captured after the by the American Army under Horatio Gates. The victory humiliates the British Army, and brings France into the war on the side of the Americans.
 * The Great Siege of Gibraltar in June 1779 – February 1783. During the American Revolution a combined Franco-Spanish force lays siege to a British garrison for nearly four years. A 'Grand Assault' of over 60,000 men, and 150 assault vessels by the bisieging forces on September 1782 results in total disaster, with over 6,000 casualties and dozens of ships lost.

19th century

 * The Battle of Bladensburg. War of 1812, the rout of American forces in 1814 by a smaller force of raiding British regulars and Marines under General Robert Ross, which led to the British Burning of Washington. Described in an 1816 American poem as the Bladensburg Races after American troops ran through the streets of Washington in disarray. Ross was later killed by American soldiers on campaign during the Battle of North Point but was subsequently honoured posthumously as Ross of Bladensburg. His US opposite, General William H. Winder, was later court-martialled but cleared of blame.
 * The Battle of New Orleans. War of 1812. On January 8, 1815, a British force of more than 8,000 attacked entrenched positions manned by 4,000 Americans commanded by Andrew Jackson, and were smashed—losing more than 2,000 killed and wounded, to 13 Americans killed and 39 wounded. Ironically, it was fought after the Americans and British had agreed to peace - the Treaty of Ghent, Belgium, but sea-borne communications were too slow to prevent the battle.
 * The Battle of San Jacinto. Texas Revolution, April 21, 1836. General Santa Anna, fully aware that the Texian Army was very nearby, ordered his exhausted army to take an afternoon siesta and failed to post standing skirmishers or sentries. This led to an absolute rout when the Texian Army under command of General Sam Houston made a surprise attack in broad daylight, with 630 of Santa Anna's 1400 troops killed against 9 Texians and almost the entire remainder captured, including Santa Anna himself. This also proved to be the decisive battle of the entire war as the Republic of Texas then successfully negotiated with Santa Anna the withdrawal of all of his remaining troops from Texan soil at the Treaties of Velasco.
 * The Charge of the Light Brigade. Crimean War, 1854. A British officer misinterpreted an order and led a suicidal charge against the Russian guns. ("Not tho' the soldier knew, someone had blunder'd" &mdash; Tennyson)
 * Battle of the Little Bighorn. June, 1876 - Montana Territory. Lieutenant Colonel George Custer attacks a superior force of armed Native American warriors, gets himself and his entire command killed, the only survivor being a lone horse. 268 U.S. troopers were killed and 55 were wounded.
 * Battle of Isandlwana. A Zulu impi armed mostly with spears destroys two British battalions armed with rifles in a Pyrrhic victory.
 * Napoleon's Invasion of Russia in the summer and winter of 1812 where Napoleon lost almost all of his troops; it was the turning point of the Napoleonic wars.
 * William Elphinstone's disastrous retreat in 1842 during the First Anglo-Afghan War led to the loss of almost his entire command.
 * Both the Battle of Fredericksburg and the Battle of Cold Harbor become horrible one-sided battles in which Union advances on entrenched Confederate units result in horrendous casualties during the American Civil War.
 * Pickett's Charge by the Confederates in the Battle of Gettysburg was easily repulsed and, along with the cost of the previous two days of the battle, permanently crippled the Army of Northern Virginia.
 * HMS Victoria collided with HMS Camperdown and was sunk with the loss of 358 lives after the fleet commander George Tryon ordered a sudden turn during maneuvres in 1893.
 * The Battle of Adwa fought between the Italians and Ethiopians in 1896. The Italians were completely defeated and the battle confirmed the independence of Ethiopia.

20th century

 * The Battle of Tsushima – the Russian Baltic fleet was sent halfway around the world in a suicidal attack on the Japanese in the Tsushima Straits in 1905.
 * The Battle of Kolubara - a well supplied Austria-Hungarian invasion force of 450,000 is crushed by a poorly armed force of 250,000 Serbians in 1914. As well as the invasion being repulsed, over 200,000 Austria-Hungarians were killed, captured, or wounded.
 * The Battle of Gallipoli in 1915 and early 1916. A combined British, Commonwealth and French attempt to capture Istanbul fails completely at the Gallipoli peninsula.
 * The Battle of the Somme - an attempt by Allied forces to break the German line during WWI, remembered most for the incredibly high casualties suffered by the British Army. Over 19,000 British soldiers were killed on the first day of the battle, due in part to ineffective artillery preparation of the objective and a gross underestimation of German fortifications.
 * The Battle of Annual in 1921. A 20,000-man Spanish-Moroccan force in the Rif was annihilated by Abd el Krim's much smaller rebel force, initiating the Rif War.
 * The Maginot line - although from a strictly technical viewpoint the line itself functioned as designed, it was emblematic of a deeply flawed defensive strategy.
 * The Battle of France in 1940 - the French Army moved to meet the Germans inside Belgium, believing the Maginot Line would force the Germans to rerun the Schlieffen Plan, but was cutoff by a German advance through the Ardennes, which the French had believed was impassable for tanks. Unlike World War 1 when trench warfare caused Paris to stay French for four years, the entire Battle for France was over in 2 months.
 * Operation Compass in North Africa during winter 1940/41. The Italian army built their forts too far apart so they were not mutually supporting, and lacked tanks or other mobile forces. A British force of 35,000 men was able to rout the Italian army of 150,000, forcing them back 800 km and capturing around 3 times their own number for almost no losses.
 * Operation Typhoon, the failed German drive towards Moscow in 1941 was exacerbated by the German decision to not bring along any winter clothing and vehicle antifreeze.
 * The fall of Singapore (believed to be an impregnable fortress) in February 1942 to two Japanese divisions was the largest surrender of British-led troops in history and destroyed the linchpin of the American-British-Dutch-Australian Command. The British Commonwealth overestimated the size of the Japanese invasion force which was ⅓ of the size of the defending force and surrendered.
 * The naval Battle of Midway. Admiral Yamamoto of the Imperial Japanese Navy attempted to invade the American navy base at Midway Island. U.S. Navy intelligence broke his codes and anticipated the attack. The Imperial Japanese Navy lost four fleet carriers in three days partly due to the decision to refuel their aircraft simultaneously on the flight deck, making the fuel hoses and aircraft vulnerable to bombing.
 * The Allied Dieppe Raid on German-occupied France in 1942 ended with ~60 % of the attacking force being lost in battle without any of the major objectives of the raid achieved.
 * The Battle of Stalingrad in the winter of 1942/43 was one of the turning points of World War II. The German General Friedrich Paulus failed to keep a mobile strategic reserve and the entire (and formerly invulnerable) 6th Army was surrounded on all sides by a rapid Soviet flanking attack. Rubble caused by excessive bombing and artillery by the German troops had left their tanks unable to effectively enter the city. The German troops in Stalingrad surrendered even though Adolf Hitler had promised that they would never leave the city.
 * Operation Bagration (1944) the Soviet summer offensive sliced through the Germans and reached Poland within two weeks, the offensive also destroyed army group centre, the backbone of German forces in the east.
 * Operation Market Garden A British plan to encircle the Ruhr Area and end the war by Christmas. The plan failed due to the entire army having to advance along a single road, making them vulnerable to attack on both sides, costing over 15,000-17,000 Allied casualties.
 * Battle of Tianquan, Chinese Communists defeat much larger Nationalist opposition in 1950.
 * The Battle of Dien Bien Phu, which forced the French to withdraw from northern Vietnam in 1954.
 * The Bay of Pigs Invasion, a United States-backed 1961 attempt to overthrow Cuban President Fidel Castro with 1,500 Cuban exiles. Not only were the exiles heavily outnumbered when they reached the bay, but the US-promised air support never came to aid the exiles.
 * The Six-Day War, in response to Arab threats of invasion, Israel launched surprise air attacks which almost completely destroyed the Air Forces of Egypt, Jordan, and Syria, then launched a series of ground, air, and naval attacks which saw the capture of the Sinai from Egypt, the West Bank from Jordan, and the Golan Heights from Syria, and heavy Arab losses in personnel and material.
 * Tet Offensive an offensive started by North Vietnam and Vietcong in 1968. Although the offensive was a military defeat for the communists, it had a profound effect on the US government and shocked the US public, which had been led to believe by its political and military leaders that the communists were, due to previous defeats, incapable of launching such a massive effort.
 * The Battle of Longewala - during the western theater of the Indo-Pakistani War of 1971, Pakistan launched a large-scale offensive (involving of 2,800 soldiers, 65 tanks and more than 130 other military vehicles) to capture a small Indian Army post at Longewala manned by 120 personnel and one jeep-mounted RCLR. Despite numerical inferiority, the Indian Army successfully repelled the invasion and destroyed or captured more than 100 Pakistani tanks and military vehicles.
 * Operation Eagle Claw, a U.S. attempt to rescue hostages in Iran. This operation was marked by a series of mechanical and communication failures that led to the deaths of eight American servicemen, and failed to rescue the hostages.

21st century

 * The 2008 attack on Omdurman and Khartoum was an attempt by the Justice and Equality Movement (JEM), a Darfur-based rebel group, to capture the Sudanese cities of Khartoum (the capital) and Omdurman (the largest city). The attacks were repulsed by Sudanese military and police forces. The bodies of 90 JEM rebels were found, with dozens more scattered outside the city, and two thirds of their 180 vehicles were destroyed. Scores of JEM rebels were captured, and many were executed.