Final answer:
The major battle that began the Allied liberation of Western Europe in World War II was the D-Day invasion on June 6, 1944. Codenamed Operation Overlord, this successful launch of Allied forces in Normandy marked a significant turning point in the war, leading to the eventual defeat of Nazi Germany and Victory in Europe Day.
Step-by-step explanation:
The major battle of World War II that began the Allied liberation of Western Europe was D-Day, the largest amphibious invasion in history. This pivotal event, codenamed Operation Overlord, took place on June 6, 1944. Despite facing formidable German defenses along the Atlantic Wall, Allied forces, comprising American, British, and Canadian troops, successfully stormed the beaches of Normandy. The operation resulted in a significant number of casualties but ultimately succeeded in establishing a strong foothold in France, leading to the liberation of Paris on August 25, 1944, and marking the beginning of the end of Nazi occupation in Western Europe.
Although great strides were made following the Normandy invasion, the Allies encountered stiff resistance from German forces, resulting in a slow but steady push towards Germany. The Western Front opened by D-Day strategically diverted German troops and resources, easing the pressure on the Soviet Red Army advancing from the East. This coordinated effort on multiple fronts contributed to the eventual defeat of Nazi Germany and the Victory in Europe Day (V-E Day) on May 8, 1945.