How far had Nazi Germany conquered Europe by 1940?

After Poland fell in September 1939, the Western Front was quiet through the “phoney war”. Then Germany struck. Denmark and Norway were attacked in April 1940; on 10 May 1940 German forces invaded the Netherlands, Belgium and France.

• The main armoured thrust came through the Ardennes — hilly, wooded country the French had assumed tanks could not cross — bypassing the Maginot Line and cutting the Allied armies in two.
• Dunkirk: between 26 May and 4 June 1940, Operation Dynamo lifted around 338,000 British and French troops off the beaches. The army was saved; its heavy equipment was not. As Churchill told Parliament, wars are not won by evacuations.
• France surrendered on 22 June 1940. The north and west were occupied; the south was governed from the spa town of Vichy by Marshal Pétain, a collaborationist regime.

By summer 1940 Germany dominated most of western and central Europe. Britain, with its Empire and Commonwealth, fought on alone.

Why was Germany unable to conquer Britain?

Hitler’s planned invasion, Operation Sea Lion, could not be launched until the Luftwaffe had destroyed the RAF — barges crossing the Channel would be helpless under air attack. So the Battle of Britain (summer–autumn 1940) decided it.

• Radar (the Chain Home stations) and the Dowding system let Fighter Command scramble squadrons only where they were needed — no wasteful standing patrols.
• Hurricanes and Spitfires fought over home ground: a British pilot who bailed out could fly again; a German one was a prisoner. German fighters could stay over Britain only briefly before fuel ran low.
• In September 1940 the Luftwaffe switched from attacking airfields to bombing London. That relieved the pressure on Fighter Command at its most dangerous moment.
• Unable to win air superiority, Hitler postponed Operation Sea Lion in September 1940. It was never launched.

Consequence: Britain stayed in the war — which mattered enormously, because it kept a base from which the Allies could later bomb Germany, fight the Battle of the Atlantic and, in 1944, invade occupied Europe.

Why Sea Lion never sailed

Why did Hitler invade the Soviet Union in 1941?

On 22 June 1941 Germany launched Operation Barbarossa — the largest invasion in history — tearing up the Nazi–Soviet Pact of 1939.

• Ideology: Hitler had always intended to destroy “Jewish Bolshevism” and seize Lebensraum (living space) in the east for German settlers.
• Resources: Soviet grain, coal and above all the oil of the Caucasus would make Germany self-sufficient and immune to blockade.
• Strategy: Hitler believed the USSR would collapse in weeks, and that knocking it out would also end Britain’s last hope of a continental ally.

The opening months brought spectacular German successes — vast encirclements and millions of Soviet prisoners. But the advance stalled in front of Moscow in December 1941: distances were huge, supply lines overstretched, the winter savage, and the Red Army was not finished after all.

Why was Stalingrad a turning point?

In 1942 the Germans drove south towards the oilfields, and into the city of Stalingrad. The fighting from August 1942 was street-by-street and house-by-house. In November 1942 the Soviets launched Operation Uranus, punching through the weaker Romanian armies guarding the flanks and encircling the German Sixth Army. Hitler forbade a breakout. Trapped, freezing and starving, Field Marshal Paulus surrendered in early February 1943.

• An entire German field army was destroyed — losses Germany could not replace.
• The strategic initiative in the east passed to the USSR: from 1943 the Red Army was advancing, not retreating.
• Soviet morale soared; German morale and the myth of invincibility were shattered.

Judgement: Stalingrad, together with the failure before Moscow, meant Germany could no longer win in the east. From then on the question was how long it would take the Allies to close in.

How did US–Japanese relations break down?

Japan was a crowded, resource-poor industrial power that wanted an empire. It seized Manchuria in 1931 and launched a full war against China from 1937. When France fell in 1940, Japan moved into French Indochina.

• The USA objected to Japanese expansion in China and responded with economic pressure: restrictions on exports, then, in 1941, the freezing of Japanese assets and an embargo on oil.
• Japan imported most of its oil from the USA. The embargo left its leaders with a stark choice: withdraw from China — humiliating and unthinkable to the militarists — or seize the oil of Southeast Asia and fight the USA.
• Negotiations in late 1941 went nowhere. Japan chose war, and planned to smash the US Pacific Fleet first so that it could conquer Southeast Asia unopposed.

How successful was the attack on Pearl Harbor?

On the morning of 7 December 1941, Japanese carrier aircraft struck the US Pacific Fleet at Pearl Harbor in Hawaii without a declaration of war. Battleships were sunk or crippled, aircraft destroyed on the ground, and around 2,400 Americans were killed.

• What went right for Japan: total surprise; the US battleship line was wrecked; Japan gained months of freedom to conquer Southeast Asia.
• What went wrong: the American aircraft carriers were at sea and survived — and carriers, not battleships, would decide the Pacific war. The dockyards, repair shops and fuel storage were largely untouched.
• The biggest consequence: a divided, isolationist America was united overnight. The USA declared war on Japan on 8 December 1941; Germany declared war on the USA on 11 December 1941. The industrial giant was now in the war — in both theatres.

Why were the Japanese so successful at first? Malaya & Singapore

Japanese forces landed in northern Malaya in December 1941 and drove south. On 10 December 1941 Japanese aircraft sank the British capital ships Prince of Wales and Repulse — proof that warships without air cover were doomed. Singapore, Britain’s great naval base, surrendered on 15 February 1942; tens of thousands of Allied troops marched into captivity.

• Air and naval superiority — the Japanese had modern aircraft and used them ruthlessly; the defenders had few.
• Tactics — fast, light, jungle-trained troops (famously using bicycles on rubber-estate roads) repeatedly outflanked defenders who expected them to be roadbound.
• British complacency and poor preparation — Singapore’s defences were designed around a threat from the sea, and reinforcements arrived too late and untrained for jungle war.
• Overstretch — Britain was fighting Germany and Italy at the same time; the Far East came last for men and aircraft.

Significance: the fall of Singapore was the greatest defeat in British military history and did lasting damage to the idea of European invincibility in Asia.

Why was Midway a turning point?

At the Battle of Midway (4–7 June 1942) US codebreakers had worked out where and roughly when the Japanese would strike. Admiral Nimitz laid an ambush. American dive-bombers caught the Japanese carriers at their most vulnerable — decks crowded with fuelled and armed aircraft.

• Japan lost four fleet carriers — and, just as importantly, hundreds of superbly trained naval aircrew it could not replace.
• The USA lost the carrier Yorktown, but American shipyards were already building replacements at a rate Japan could never match.
• Result: Japan lost the initiative in the Pacific. From Midway onwards, the Americans advanced and the Japanese defended.

Pearl Harbor: what was really lost?

The impact of bombing on civilians

The Blitz (September 1940 – May 1941). After the Battle of Britain the Luftwaffe bombed London and Britain’s industrial cities night after night. Around 40,000 civilians were killed. Coventry was devastated on the night of 14 November 1940. Families slept in Anderson shelters and Underground stations; children were evacuated; the government censored news and promoted the idea of the “Blitz spirit”. Morale bent — there was panic, looting and exhaustion — but it did not break, and war production kept going.

Allied bombing of Germany (1943–45). The RAF bombed by night and the USAAF by day. Hamburg was hit by Operation Gomorrah in July 1943, creating a firestorm that killed tens of thousands. Dresden was bombed in February 1945, killing roughly 25,000 people according to a later official commission of historians.

The debate: supporters argue area bombing tied down German fighters, guns and manpower and wrecked transport and oil supplies. Critics argue it killed enormous numbers of civilians, did not break morale (any more than the Blitz broke Britain’s) and was of doubtful morality — especially the attack on Dresden so late in the war. Cambridge rewards you for arguing both sides.

Nazi rule in occupied Europe

Nazi occupation was harshest of all in Poland, which German racial ideology treated as land to be cleared and its people as slaves.

• Poland was carved up: territory was annexed to the Reich, and the rest ruled as the General Government. Polish leaders, priests, officers and intellectuals were rounded up and murdered; universities and secondary schools were closed.
• Poles were used as forced labour. Food was seized; rations for Poles were set far below German levels.
• Polish Jews were forced into sealed ghettos — the Warsaw ghetto was sealed in 1940 — where starvation and disease killed enormous numbers.
• After the invasion of the USSR in 1941, the Einsatzgruppen shot Jews and others in mass killings. At the Wannsee Conference of January 1942 officials coordinated the “Final Solution”. Extermination camps were built in occupied Poland — Auschwitz-Birkenau, Treblinka and others.
• In the Holocaust, around six million Jews were murdered — roughly half of them Polish Jews. Roma, disabled people, Soviet prisoners of war and political opponents were also murdered in vast numbers.

Why this matters: the Holocaust was not a by-product of the fighting. It was a deliberate policy, carried out under cover of war, in the territories the Nazis had conquered.

How did Japanese control affect people’s lives?

Japan claimed to be liberating Asia from European empires through the Greater East Asia Co-Prosperity Sphere. In practice, occupation was exploitative and brutal.

• Sook Ching (February–March 1942): Japanese forces screened the Chinese population of Singapore and Malaya and massacred thousands of men suspected of anti-Japanese sympathies.
• Forced labour: Asian labourers (romusha) and Allied prisoners of war were sent to build the Burma–Siam railway, where huge numbers died of disease, starvation and ill-treatment.
• Economic collapse: the Japanese issued occupation currency (nicknamed “banana money”) which became almost worthless; rice was rationed, food ran short and a black market flourished.
• Control: the Kempeitai (military police) used torture and public executions; schools taught Japanese; Chinese communities were singled out for the worst treatment, while some Malay and Indian nationalists were courted.

How effective were resistance movements?

• France: resistance ranged from underground newspapers and escape lines to armed maquis bands in the hills. Britain’s SOE supplied weapons and radios; de Gaulle’s Free French provided a rallying point. Before D-Day in June 1944 the Resistance sabotaged railways and telephone lines, delaying German reinforcements. But reprisals were savage — the whole village of Oradour-sur-Glane was massacred in June 1944.
• Malaya: the communist-led MPAJA (Malayan People’s Anti-Japanese Army) fought a jungle guerrilla campaign, supported from 1943 by the British Force 136. It could harass, gather intelligence and tie down Japanese troops, but it could not liberate the country.

Balanced judgement: resistance movements rarely defeated occupiers on their own. Their value was in intelligence, sabotage and morale — and they had to be weighed against the terrible cost of reprisals against civilians.

Which theatre, which theme?

Tap a card, then tap the column it belongs in.

The Allied advance through Italy

After clearing North Africa, the Allies invaded Sicily in July 1943 (Operation Husky). The shock brought down Mussolini, who was dismissed and arrested on 25 July 1943. Italy surrendered in September 1943 — but German troops immediately occupied the country and fought a stubborn defensive campaign up the mountainous peninsula.

• Monte Cassino held the Allies up for months in 1944; Rome was only liberated in June 1944.
• Was it worth it? Churchill called Italy the “soft underbelly” of Europe; it proved anything but. Still, the campaign knocked Italy out of the war, gave the Allies airbases, and tied down German divisions that could not be used in Normandy or Russia.

Why was Nazi Germany on the point of collapse by April 1945?

Germany was being crushed from every direction:

• D-Day, 6 June 1944. Allied forces landed in Normandy — the largest seaborne invasion ever mounted. Paris was liberated in August 1944 and the Allies pushed towards the Rhine. Hitler’s last counter-attack in the Ardennes (the Battle of the Bulge, December 1944) failed and used up his remaining reserves.
• The Soviet advance from the east was relentless after Stalingrad and Kursk, sweeping through eastern Europe and into Germany itself.
• Bombing had wrecked German cities, transport and — decisively — oil production, leaving tanks and aircraft without fuel.
• Germany was out of men and materials, fighting on two major fronts against enemies with far greater resources.

Soviet troops fought into Berlin in April 1945. Hitler killed himself on 30 April 1945, and Germany surrendered unconditionally in May 1945.

Why were the Allies able to defeat Japan?

• Guadalcanal (August 1942 – February 1943) — a long, brutal land, sea and air battle. Japan was forced onto the defensive in the South Pacific.
• Island-hopping — instead of storming every island, the Americans captured key islands with airfields and bypassed and cut off the rest, leaving Japanese garrisons to wither. Each hop brought US bombers closer to Japan.
• Industrial power and submarines — US shipyards out-built Japan many times over, and US submarines throttled the tankers and freighters on which the Japanese war economy depended.
• Bombing of Japan — B-29s firebombed Japanese cities from 1944–45; the raid on Tokyo on 9–10 March 1945 killed tens of thousands.
• Okinawa (April–June 1945) — appallingly costly for both sides, with kamikaze attacks and huge civilian deaths. It convinced US planners that invading Japan itself would cost a fearful price.
• The atomic bombs — Hiroshima on 6 August 1945 and Nagasaki on 9 August 1945, each killing tens of thousands instantly and many more later from burns and radiation. The USSR declared war on Japan on 8–9 August 1945 and invaded Manchuria. Japan announced its surrender on 15 August 1945 and signed it on 2 September 1945.

The atomic debate: was the bomb used to end the war quickly and avoid a bloodbath in an invasion — or to force a surrender before the USSR could share in victory, and to demonstrate American power? Historians still argue. So should you, with evidence on both sides.

Island-hopping

How did the Allies consolidate victory?

• Germany was divided into four occupation zones (American, British, French and Soviet), with Berlin — deep inside the Soviet zone — likewise split into four sectors. The Allies began denazification, disbanding Nazi organisations and removing Nazis from public life.
• The Nuremberg Trials (November 1945 – October 1946) tried leading Nazis before an International Military Tribunal for crimes against peace, war crimes and crimes against humanity. Of the 22 defendants tried, 19 were convicted and 12 were sentenced to death.
• Japan was occupied by the USA under General MacArthur. The armed forces were disbanded, the political system reformed and a new, democratic constitution came into force. The Emperor kept his throne but renounced his divine status — a decision taken to keep Japan governable.
• The Tokyo trials (the International Military Tribunal for the Far East, 1946–48) tried Japanese leaders, including the wartime prime minister Tojo, who was executed.

Looking forward: the wartime alliance did not survive the peace. The division of Germany and the occupation of eastern Europe by the Red Army led directly into the Cold War.

Turning point → why it mattered

Tap an event on the left, then its significance on the right.

Name the operation

Build the timeline

Tap the events in order, earliest first.

Two theatres, one judgement

Evaluating the bombing debate

The essentials to remember

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