World War 2 was the largest and costliest war in human history. The deaths directly and indirectly caused by the war may have reached 60 million. It was the product of not only of a profound disequilibrium in world affairs; it reflected deep hatreds and powerful imperial ambitions inherited from the Great War of 1914-18, where lay the seeds of the second, and larger conflict.

The end of the conflict produced a reconfiguration of the world. Britain and France had to give up the global empires they had fought to defend. Communism came to control much of Asia and eastern Europe, while the United States used its economic and military power to preserve its interests on the non-communist world.

The war had brought a precious peace, but only at the price of misery for tens of millions caught in its merciless crossfire.

World War 2 began when Poland was invaded by Nazi Germany. As a reaction France and Great Britain declared war on Germany. The Soviet Union also invaded Poland from the east in accordance with the non-aggression pact it had with Germany. Afterwards the Soviets invaded Finland. The Soviet attack on Finland ended with the Treaty of Moscow, in which Finland lost a part of it's territory.

The Western front of World War 2 began when Germany invaded and occupied Norway and Denmark. After the battle of France, Germany occupied Luxembourg, Holland, Belgium and France. During the battle of Britain, Nazi Germany tried the force a British surrender. The war was resumed in Western Europe with the Allied landings in Normandy, codenamed Operation Overlord. The success of these landings led to the liberation of France and subsequent defeat of Germany by the Allied Expeditionary Force.

The European Eastern front of World War 2 started when Nazi Germany launched Operation Barbarossa, the invasion of the Soviet Union. After the Germans failed to capture Moscow, and the subsequent defeats at Stalingrad and Kursk the initiative changed hands. The campaign ended when the Soviet Red Army defeated Nazi Germany during the battle of Berlin.

The North African campaign was fought between the Allies and the Axis powers. Many of them had colonial interests in the region. The campaign started with the Italian declaration of war on Britain. During operation Compass the British destroyed the Italian 10th Army and the German Afrika Korps was dispatched to aid the Italians. A series of battles for control of Libya and parts of Egypt followed. The campaign reached its climax with the second battle of El Alamein when the British forces defeated the Germans. After this defeat, and the concurrent Anglo-American landings in French Morocco and Algeria code named operation Torch, the Germans started their retreat towards Tunisia. There they were defeated by the combined forces of the Allied armies.

After the defeat of the German Afrika Korps the Allies organized the invasion of Sicily. The success of this operation led to the Allied invasion of Italy. After a successful D-Day the Allied forces started their march towards Rome. The city was captured after the Allies won the battle of Monte Cassino and Anzio landings. After the fall of Rome the Germans retreated in Northern Italy, where they were defeated the following spring.

The Tehran, Potsdam and Yalta conferences were important meetings held between the 3 major Allied powers: United States, Soviet Union and Great Britain. The meetings were pivotal in setting Allied strategy during the war, but also in shaping the world after the conflict had ended.