The 5 Most Significant Battles of the Second World War

Second World War battles took place across the globe; some lasting days, others months or even years. But which are the most significant? Here, Professor Evan Mawdsley from the University of Glasgow lists the battles that had the most impact upon later military and political events, and indeed the outcome of the war itself

Second World War

A ‘battle’ is defined here as an event occurring in a particular place and over a relatively short time-span; the shortest of these battles lasted 90 minutes, the longest three months. Indeed, the ‘battle of the Atlantic’ was extremely significant, but it was not a battle: instead, it was a six-year series of battles, none of which was – in itself – decisive. The same is true of the five-year Allied bomber offensive.

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Looking at the war in terms of ‘battles’ tends to increase the apparent importance of the Russians; they fought more battles and destroyed most of the German army. For me, the European war was inherently more significant in the military and strategic terms than the Asia-Pacific war (this was also the view of the British, American and Soviet war leaders).

Had Hitler knocked Britain or the USSR out of the war he would have made the Third Reich a real ‘world power’, and German-dominated Europe would have been unassailable. In contrast Japan, at that time a second-rate regional power, could not have been a global military threat on its own.

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Furthermore, ‘most significant’ is not the same as ‘most decisive’, ‘biggest’, ‘greatest’, ‘bloodiest’, ‘most skillful’ or ‘most successful’. Instead, ‘significant’ means that the battle had a major effect on later military and political events, if not the final outcome of the war.

If I had been able to choose 15 significant battles I might have added Wavell’s first Libyan offensive (December 1940), the battle of Smolensk (1941), the invasion of Sicily (1943), the air-land-sea battle of the Mariana Islands (1944) and the Vistula-Oder Operation (1945).

1. France, May 1940

The rapid and unexpected conquest of the Low Countries and northern France in four weeks was the supreme example of German mastery of mobile warfare. It was also the war’s most significant battle.

The back of the French army was broken. Hitler would gain control over western Europe (and Fascist Italy entered the war). Everything else in 1940–45 was a consequence of this victory. The German blunder of allowing the British Expeditionary Force to escape through Dunkirk was also significant; Britain would remain a threat, and Hitler’s victory was incomplete. But Stalin’s hope for a long mutually destructive war between the capitalist powers was undone; Russia itself was now threatened.

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2. Battle of Britain, August–September 1940

The Luftwaffe mounted mass daytime raids against RAF bases and later London, hoping to gain air superiority and force Britain to make peace – preparations for the invasion began.

Britain possessed a radar-controlled air defense system and a powerful Royal Navy. Public morale did not crack, high German losses forced a change in mid-September to sporadic and less effective night bombing, and the arrival of autumn weather made invasion impractical.

The battle demonstrated to Germany (and the USA) that Britain could not be easily knocked out of the war. The Americans sent help; Hitler decided that he needed to invade the USSR.

3. Operation ‘Barbarossa’, June–July 1941

Hitler’s surprise attack on the USSR was the most devastating victory of the whole war; as a battle, it covered the largest area. The Wehrmacht’s first objective was achieved: the rapid destruction of the Red Army in western Russia.

‘Barbarossa’ did not achieve the larger goal of overthrowing the Soviet system and occupying all European Russia. Nevertheless, the catastrophe eventually forced the defenders to fall back 600 miles, to the outskirts of Leningrad and Moscow. The Red Army had to be rebuilt; it would not drive the occupiers out of the USSR until the autumn of 1944.

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4. Moscow, December 1941

The successful Red Army surprise counter-offensive in front of Moscow, which began on 5 December, was the second most significant battle of the entire war.


The Russians would have bad defeats later, and the Germans would suffer much greater losses at Stalingrad in 1942–43. But the setback at Moscow meant that the Blitzkrieg strategy of Hitler and his generals had failed; the USSR would not be knocked out of the war in just a few months.

The northern and central parts of the Soviet front now held firm. And the Third Reich could not win a war of attrition.

German tanks and infantry advancing into a village in the district of Volokolamsk during the battle of Moscow. (Photo by Arthur Grimm/ullstein Bild via Getty Images)
5. Pearl Harbor, 7 December 1941

The fighting lasted only 90 minutes and was very one-sided, but this was undoubtedly a major battle – six aircraft carriers with more than 400 planes attacked the main American naval base.

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Crippling the enemy battleship fleet allowed Japan to overrun south-east Asia without interference. But the ‘Day of Infamy’ threw a hitherto cautious American public whole-heartedly behind the war with Japan and Germany – although early preoccupation with Pacific defense delayed the sending of American forces to Europe.

Fierce anti-Japanese sentiment also led to a readiness to use firebombing and nuclear weapons three years later.