Even before the first German soldier crossed the frontier into the USSR, the Nazi government in Berlin had a plan for administering occupied Russia.

The German invasion of the USSR went brilliantly for the first 2-3 weeks, but instead of collapsing as expected, the Red Army only got stronger.

On June 22, 1941, Germany began an invasion of its erstwhile trade partner, the USSR. 

The Dust Bowl ravages the central United States, Charles Lindbergh's infant son is kidnapped, the America First movement opposes US involvement in the war.

Germany executes its invasions of Yugoslavia and Greece, and the Axis encourages an anti-British coup in Iraq.

As Germany made preparations to assist its ally Italy in the war against Greece, a coup in Yugoslavia prompted Adolf Hitler to order the invasion of that country as well. 

In summer of 1940, even as the Battle of Britain was just getting started, Adolf Hitler was already laying plans for war with the Soviet Union.

After the fall of Poland, British Intelligence's codebreaking operation at Bletchley Park became the center of efforts to decrypt messages from the Germans' supposedly unbreakable Enigma machine.

The British had been hugely successful at breaking German codes in the First World War. The Germans were determined not to let that happen again. This time they had Enigma, a code machine that produced messages that could not be decrypted. Or so the Germans believed.

The navy Germany had at the outbreak of the Second World War was only a small fraction of what the Allies had arrayed against it. But the Fall of France and the entry of Italy into the war changed things dramatically and created opportunities at sea that Germany had never had in the last war.