German flamethrowers at Battle of Verdun Osprey Publishing

The 10 Deadliest Battles In History

A look at some of most infamous campaigns in the history of war.

German flamethrowers at Battle of Verdun Osprey Publishing

All wars have the potential to be deadly to those who serve their country on the front line but there are those that stand out in history for the profound human cost they inflicted on the combatant nations.

Though the question of just how a rundown of these deadliest wars might be calculated has been the subject of academic debate, as has the question of whether or not wars are getting more deadly. Determining this involves factoring in advances in technology and weaponry, and increases in population, all of which may account for the huge loss of life in war seen during the 20th Century. 

Given this complex background, determining which have been the deadliest battles within these wars can also be challenging. One might say it is worth remembering there is a certain truth to the phrase popularised by Mark Twain that there are “lies, damned lies, and statistics”.

This is to say that, broadly speaking, statistical figures and what they appear to reveal should generally be questioned and viewed skeptically.

That is certainly true when trying to interpret war data. The sheer complexity of warfare, run later through many and varied sources, makes it easy to misinterpret what happened during wars of the past.

Therefore, the exercise of making accurate and meaningful comparisons between historic battles is an enterprise that should be done with caution. A Google search of history’s 10 worst or biggest battles, or words to that effect, will turn up plenty of lists.

Yet to ensure a list is truly trustworthy, it should probably be one put together by someone like Micheal Clodfelter. He has compiled casualty data from wars and battles across the centuries, and done so as comprehensively as possible.

In the opening to his book, ‘Warfare and Armed Conflicts: A Statistical Reference to Casualty and Other Figures, 1500 – 2000’, Clodfelter makes the following point:

“Usually, the longer the battle and the larger the battlefield, the more uncertain the numbers involved.”

The methodology he employed to cut through this complexity involved comparing battle reports with medical records. Yet, he is still upfront about the fact that, despite this methodical approach, any of his figures are still open to question. Such is the complexity of the subject matter.

Thus, the following list is based upon his best accounting of the 10 most deadly battles in history, with “deadly” meaning number of people killed. 

It is a grim accounting, though one that is useful from an historical perspective. The sheer scale of each of these campaigns helps explain why the World Wars they took place within were so stunningly destructive. Battles as big as these have also left permanent imprints on the collective consciousness of those nations and peoples who fought in them, something that remains in the background of politics and international relations today.

Each battle follows in ascending order. The figures do not include civilian dead (unless stated), or POWs who later died in captivity. Also please note that Clodfelter says the estimates of military dead given for the Battles of Hankow, Beylorussia and Berlin are taken from particularly broad estimates that are more unreliable than the other figures here.

The 10th Most Deadly Battle In History: The Battles of the Frontiers

Essentially a larger battle that included a number of smaller ones (including the Battle of Mons), the Battles of the Frontiers was the main German effort against France in the opening days of the First World War.

In the years before the war, the Chief of the Imperial General Staff of the German Army, Count Alfred von Schlieffen, had devised a scheme of attack meant to bypass the bulk of the French Army and capture Paris quickly. Known as the Schlieffen Plan, it placed the bulk of the German efforts in the very north of France and in Belgium, when the French were expecting to meet greater German resistance further south.

In the event, German commanders carrying it out between August 14 and 25, 1914 did not follow it to the letter, though its general scheme was followed and meant that the bulk of the opening German war effort did take place and was resisted in the north, before finally being stopped at the Battle of the Marne. As horrible as they were to live in, trenches saved lives during the First World War, and that is a large part of why so many lives (125,000) were lost in this campaign, which happened before trench lines had been constructed.

Passchendaele Battlefield
A picture of the Passchendaele battlefield (image from ‘World War I’ by Ken Hills © Cherrytree Press Ltd)

The 9th Most Deadly Battle In History: Passchendaele

Synonymous not just with death but also with slime and mud, the Battle of Passchendaele occurred between July 31 and November 10, 1917. 

It went on through some of the wettest conditions seen during the war, and its muddy, water-filled craters have become the iconic image for war on the Western Front more generally – and not without reason, since horrible muddy trenches were hardly confined to this engagement. They were just particularly bad during it.

A contest primarily between the British the Germans, who vied for control of part of Belgium, total deaths, by Clodfelter’s accounting, reached 151,000 – though, as with other battles this large and confused, estimates vary considerably.

The 8th Most Deadly Battle In History: Moscow

Arguably the turning point of the Second World War, the Battle of Moscow took place between November 15 and December 5, 1941 (according to Clodfelter’s accounting) and it ended the German advance towards the Russian capital.

Together with the Battle of Stalingrad, the Battle of Moscow reversed the momentum of the German advance into the USSR that had been so rapid and determined since June of 1941. It was then pressed back in the other direction, leading eventually to the Battle of Berlin and destruction of Nazi Germany.

The cold was as much of a factor as soldiers and material, with temperatures dropping as low as minus 40 degrees Fahrenheit. 

There were a total of 155,000 battle deaths.

The 7th Most Deadly Battle In History: The Brusilov Offensive

Taking place on the Eastern Front during the First World War, the campaign drew its name from General Alexei Brusilov, the commander of Russian forces at that time.

Its battle area encompassed a front of some 300 miles wide and it lasted from June 4 to September 20, 1916, resulting in 215,000 battle deaths.

It aided Russia’s allies elsewhere in the war, particularly Italy, which had been struggling against the Austro-Hungarian Empire, Germany’s major ally in the war. The Germans too were militarily weakened, having to transfer forces from elsewhere to the east as a result of the overwhelming Russian attack, though it was Austria-Hungary that suffered most, being significantly weakened by the campaign.

In this way, it helped reduce the dependency of Germany’s main ally and weaken it for eventual defeat on the Western Front in 1918.

The 6th Most Deadly Battle In History: Verdun

In what was largely a defensive theatre of war for them, the Battle of Verdun is unusual is being one of the few occasions when the Germans launched an offensive on the Western Front in World War 1.

The attack was aimed right at a sacred part of the French defensive line and was conceived by General Erich von Falkenhayn.

Meant to trigger memories of the German defeat of France during the 1870 – 1871 Franco-Prussian War, Falkenhayn calculated that they would fling every man into defending the fort at Verdun. William Martin explains in ‘Verdun 1916’ that German troops sent in to capture the town were only given this objective as a boost to their morale, rather than being told the truth that they were meant as mere bait for the French counterattack.

The French obliged Falkenhyn, but not without causing about as many German casualties in the process, turning the campaign into a bloodbath for both sides, and leading, by Clodfelter’s reckoning, to a total of 234,000 battle deaths between February 21 and December 18, 1916.

German flamethrowers at Battle of Verdun Osprey Publishing
German soldiers use flame throwers during the Battle of Verdun – one of most horrifying aspects of already truly horrible war (image from ‘The Flamethrower’ by Chris McNab © Osprey Publishing, part of Bloomsbury Publishing)

The 5th Most Deadly Battle In History:  Hankow

This is the only battle out of Clodfelter’s most deadly list that is not within what we might think of as World Wars 1 or 2.

It was, however, part of the larger Chinese and Japanese conflict that both proceeded and in a sense became World War 2 in the Pacific. And if one considers World War 2 to have started in the 1930s in the far east, then it would fall be considered a World War 2 battle.

It involved a Japanese attack on Hankow that killed, according to Clodfelter, 250,000 soldiers, though the civilian deaths might, he says later in his book, have put the overall death toll closer to 1 million.

The 4th Most Deadly Battle in History: The Somme

This too was a First World War battle, infamous for its opening on July 1, 1916, in which Britain lost more men in a single day than ever had before or would since. Unfortunately, the carnage remained high for the duration of the campaign, which ran until November 18, 1916.

By its close, there had been 343,000 battle deaths, possibly as many as 164,000 of whom were German. 

Like Passchendaele the following year, the battle and its commander, Field Marshal Sir Douglas Haig, were controversial because of the use of attrition tactics and the high casualties this approach led to. As with Verdun, the casualty figures reveal it certainly led to enormous loss of life for both sides, which along with its vast scale has placed it so high up on this list.

The 3rd Most Deadly Battle In History: Baylorussia (or, Operation Bagration)

Whilst much of the historical focus on World War 2 in western countries centres, rightly, on importance and glittering success of D-Day and the subsequent Battle of Normandy, it is important to remember the Soviet contribution to that effort.

Formerly an ally of Nazi Germany, Stalin switched sides when Hitler unleashed the enormous Operation Barbarossa on Russia in 1941. As other battles on this list will attest, some of the most ferocious fighting of World War 2 then took place between the USSR and Nazi Germany on what became the Eastern Front of World War 2’s European Theatre. 

By 1944, the Soviets were firmly on the offensive, and between June 22 and August 29 that year they initiated Operation Bagration, which was centred initially on Belarus, but also came to encompass neighbouring territories. The operation led to 379,000 battle deaths (200,000 of whom were German, according to Soviet sources) and it forced the Germans to fight in the east, supporting the concurrent British and American effort in the west.

The 2nd Most Deadly Battle In History: The Battle of Berlin 

Essentially a sequel to earlier Soviet efforts like Operation Bagration, the Battle of Berlin took place between April 16 and May 2, 1945. 

It involved fighting both outside and inside the city of Berlin, the latter leading to fierce street fighting and German civilians being swept into the maelstrom. 

The Western Allies contributed to the offensive by bombing the city, but the ground forces that went in were entirely Soviet.

The battle culminated in the suicide of Adolf Hitler and it led to the end of the Second World War in Europe, with VE Day coming every year on May 8 to mark the formal German surrender that was agreed in the days following the battle. There were a total of 539,000 deaths during the campaign, 458,000 of whom were German combatants, according again, Clodfelter says, to Soviet sources. In fact, Clodfelter points out that statistics for the Battle of Berlin and Operation Bagration are even more broadly estimated and unreliable than the other enormous campaigns in this list. If higher level estimates were to be used, he says these two campaigns might tank even higher. 

The Most Deadly Battle In History: Stalingrad

The figures for the Battle of Stalingrad battle are shocking even by the standards of the other campaigns on this list. 

Running from August 23, 1942 to February 2, 1943, Stalingrad led to 633,000 battle deaths. Furthermore, Clodfelter points out that this does not even include deaths sustained by Italian, Romanian and Hungarian troops on the flanks of the battlefront.

The giant campaign was really a showdown between Hitler and Stalin over the city that bore the name of the Soviet dictator. Like the Battle of Moscow, it too was a turning point in a campaign that Peter Antill describes this way in ‘Stalingrad 1942’:

“ … Hitler always intended to attack the USSR in order to destroy Nazism’s main ideological opponent, to gain the economic, industrial and agricultural resources of Eastern Europe and also to induce Britain to make peace by demonstrating absolute German control of continental Europe.”

Instead, the battle would help bring about a change of fortunes that would eventually destroy Nazi Germany and doom Hitler.

For more statistics on battles and wars, read ‘Warfare and Armed Conflicts: A Statistical Reference to Casualty and Other Figures, 1500 – 2000’ by Micheal Clodfelter, ‘World War I’ by Ken Hills for a pictorial history suitable for children, and read ‘Stalingrad 1942’ by Peter Antill and ‘Verdun 1916’ by William Martin for more on these battles. Check out ‘The Flamethrower’ by Chris McNab for more on the history of this brutal weapon, as well as more illustrations. And visit Osprey Publishing for more military history.

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German attack on the Red October Steel Plant during the Battle of Stalingrad – notice the Soviets resisting in the background (image from ‘Stalingrad 1942’ by Peter Antill © Osprey Publishing, part of Bloomsbury Publishing)