As of 2026-10-12, Siege of Baghdad tops the list with 800,000 deaths.
- #1 Siege of Baghdad — 800,000 deaths
1258 Mongol conquest of the Abbasid Caliphate
The Siege of Baghdad, also known as the Sack of Baghdad, took place in early 1258. A large army commanded by Hulegu, a prince of the Mongol Empire, attacked the historic capital of the Abbasid Caliphate after a series of provocations from its ruler, caliph al-Musta'sim. Within a few weeks, Baghdad fell and was sacked by the Mongol army—al-Musta'sim was killed alongside hundreds of thousands of his subjects. The city's fall has traditionally been seen as marking the end of the Islamic Golden... Read more on Wikipedia.
Wikidata - #2 Battle of Okinawa — 200,656 deaths
1945 major battle of the Pacific War
The Battle of Okinawa , codenamed Operation Iceberg, was a major battle of the Pacific War fought on the island of Okinawa by the United States Army and United States Marine Corps forces against the Imperial Japanese Army. The initial invasion of Okinawa on 1 April 1945 was the largest amphibious assault in the Pacific Theater of World War II. The Kerama Islands surrounding Okinawa were preemptively captured on 26 March 1945 by the U.S. Army 77th Infantry Division. The 82-day battle on Okinawa... Read more on Wikipedia.
Wikidata - #3 Battle of Berlin — 200,000 deaths
1945 last major offensive of the European theatre of World War Il
The Battle of Berlin, designated as the Berlin Strategic Offensive Operation by the Soviet Union, and also known as the Fall of Berlin, was one of the last major offensives of the European theatre of World War II. Read more on Wikipedia.
Wikidata - #4 Assyrian siege of Jerusalem — 185,000 deaths
siege
The Assyrian siege of Jerusalem was an aborted siege of Jerusalem, then capital of the Kingdom of Judah, carried out by Sennacherib, king of the Neo-Assyrian Empire. The siege concluded Sennacharib's campaign in the Levant, in which he attacked the fortified cities and devastated the countryside of Judah in a campaign of subjugation. Sennacherib besieged Jerusalem, but did not capture it. Read more on Wikipedia.
Wikidata - #5 Battle of Antietam — 23,000 deaths
1862 major battle of the American Civil War
The Battle of Antietam, also called the Battle of Sharpsburg took place during the American Civil War on September 17, 1862, near Antietam Creek and Sharpsburg, Maryland, between the Army of Northern Virginia, led by Confederate General Robert E. Lee, and the Army of the Potomac, led by Union Major General George B. McClellan. Part of the Maryland Campaign, it was the first field army–level engagement in the Eastern Theater of the American Civil War to take place on Union soil. It remains the... Read more on Wikipedia.
Wikidata - #6 Massacre at Béziers — 19,000 deaths
1209 killing of Cathars during the Albigensian Crusade
The Massacre at Béziers occurred on 22 July 1209 during the sack of Béziers by Crusaders. It was the outcome of the Siege of Béziers, which was the first major military action of the Albigensian Crusade. Read more on Wikipedia.
Wikidata - #7 Battle of Wesenberg — 17,000 deaths
battle fought on February 18, 1268
The Battle of Wesenberg, Rakvere, or Rakovor, was fought on 18 February 1268 between the combined forces of Danish Estonia, the Bishopric of Dorpat, the Livonian Order, and local Estonian militias on one side, and the combined Russian forces of Novgorod and Pskov, led by Dmitry of Pereslavl, on the other. Medieval accounts of the battle vary, with both sides claiming victory. Read more on Wikipedia.
Wikidata - #8 Battle of Cutanda — 15,000 deaths
battle in year 1120 Cutanda, Spain
The Battle of Cutanda took place on 17 June 1120 between the forces of Alfonso the Battler and an Almoravid army led by Ibrahim ibn Yusuf occurring at a place called Cutanda, near Calamocha (Teruel). In the battle, Christian forces composed primarily of military from Aragon and Navarre routed the Almoravid force. Read more on Wikipedia.
Wikidata - #9 Defense of the Adzhimushkay quarry — 13,000 deaths
1942 battle in Crimea during WW2
The defense of the Adzhimushkay quarry took place during World War II, between May and October 1942, in the Adzhimushkay quarry named after the Adzhimushkay suburb of Kerch during Nazi Germany's occupation of Crimea. Read more on Wikipedia.
Wikidata - #10 Battle of Kohima — 12,000 deaths
1944 battle around Kohima, Nagaland, India
The Battle of Kohima was the turning point of the Japanese U-Go offensive into British India in 1944 during the Second World War. It took place in three stages from 4 April to 22 June 1944 around the town of Kohima, now the capital city of the state of Nagaland in Northeast India. From 3 to 16 April, the Japanese attempted to capture Kohima ridge, a feature which dominated the road by which the besieged British and Indian troops of IV Corps at Imphal were supplied. By mid-April, the small... Read more on Wikipedia.
Wikidata