From 1940, the Allied war effort received a huge boost when scientists at Bletchley Park became able to decipher encrypted instructions sent by the Nazi military command using the Enigma machine. Being able to read these messages proved to be a vital tool that arguably altered the course of the war. Without it, history might have taken a very different shape.
One of the first theatres in which the cracking of Enigma had an impact was the battle of the Atlantic, which raged throughout the war in Europe. Until the breakthrough at Bletchleythe ocean. Once in possession of vital intelligence about the enemy's location, though, an Allied fleet could divert its route and avoid significant loss of life.
