WWII: total number of soldiers deployed in Normandy 1944, by army

During the Allied invasion of Normandy in 1944, the number of Allied soldiers in the region outnumbered German soldiers by a ratio of almost 4:1. British, Canadian, and other Commonwealth soldiers numbered at almost two million men, while the U.S. deployed over 1.5 million men. The first soldiers began landing en masse on June 6. 1944, where over 155,000 men made footfall on the beaches of Normandy (or were airdropped behind enemy lines) in what is now referred to as D-Day. Through securing these beaches, the Allies were able to reinforce their numbers and resupply their frontlines, which was decisive in the eventual victory in Normandy.

In contrast, Germany had fewer than 900,000 men in the region during the invasion, as the bulk of their force was fighting the Soviets on the Eastern Front (while a smaller number was fighting in Italy, or occupying other territories). Despite the Germans being heavily outnumbered in Normandy, it still took almost three months for the Allies to push the Germans beyond the Seine river and to eventually liberate Paris on August 25.