World War II began on September 1, 1939 when Germany invaded Poland. Adolf Hitler ruled Germany. Hitler's troops invaded Denmark, Luxembourg, The Netherlands, Belgium, Norway and France. The Axis consisted of Germany, Japan and Italy. The Allies were the United States, Great Britain, China, and The Soviet Union. The Americans and British established a command system at the Arcadia Conference, which enabled them to plan and fight the war together.
In 1942, Britain and the United States discussed a French invasion across the English Channel. Britain's leader Winston Churchill and his military staff believed that in order to win the war France had to be liberated. In the summer of 1942, Allies raided the French port of Dieppe on the channel. This raid convinced the Allies that landing on open beaches would be a better option than landing at a port.
Preparations for this invasion were made throughout 1943. The code name for the invasion of Normandy was Operation Overlord.
The American General Dwight D. Eisenhower was in command of the operation. The Allies amassed large numbers of troops and equipment in southern England in preparation for the attack. Eisenhower chose Monday, June 5, 1944 as D-Day. However, D-Day was switched to Tuesday, June 6 because of rough seas. The five beaches were given code names: Utah, Omaha, Gold, Juno, and Sword. The Americans invaded Utah and Omaha Beaches. The Canadians invaded Juno Beach. The British troops invaded Gold and Sword Beach.
Germany anticipated an invasion along the northern coast of France. They made a line of fortifications called the Atlantic Wall along the coast. It was 3,000 miles long. Hitler put Rommel in charge of stopping the Allies. Rommel mined the water, brought in artillery and put up barbed wire. Large wooden posts were armed with impact detonated explosives.