The Allied Expeditionary Force, made up of the armies of Great Britain, Canada and the United States, landed on the beaches of Normandy on June 6, 1944, a date that became known in history as D-Day.
Those forces, under the command of General D Eisenhower, would steadily fight their way through northern Europe, and ultimately secure victory 11 months later following the Battle of Berlin and the death of Adolf Hitler.
But this was far from a straightforward process.
The forces of the Wehrmacht stood their ground with ferocity, and in some cases the ruin of entire towns and cities was brought about, not by gung-ho Allied soldiers, but because of the stamina of a German army that refused to surrender - German soldiers fighting to their deaths.
National Army Museum historian, Dr Peter Johnston, while speaking to Forces News, has described how the fierce fighting through the summer and winter months of 1944 and into 45, is sometimes forgotten as being the hard-fought fight that it really was.
Dr Johnston said: “I think it would be a misconception to say that it was just a logical procession from Normandy, across the Rhine and up to Hamburg for the British. The Germans were putting up a pretty tenacious and aggressive defence, they were not simply conceding ground.”
As the allies slowly but surely progressed, some the most significant fighting of the 20th Century occurred at key locations along what became known as the Siegfried Line.
In the September, British forces encountered ferocious German resistance at Arnhem, resulting in the loss of thousands of men.
Operation Market Garden, which was a plan originally conceived by Field Marshal Montgomery and which received the backing of Prime Minister Winston Churchill, was designed to give the allies a solid route into Northern Germany over the River Rhine in Holland.
The operation ultimately failed in its main mission, that of securing an invasion route into Germany, however the combat did have positive results with regards to the capture of key locations and the liberation of many towns and regions of the Netherlands, particularly Eindhoven and Nijmegen.
The captured areas were also often the launching points of the terrifying V2 Rockets, used by the Germans to rain down terror on British cities including London.
The fighting was substantial for other allies, too.
During Christmas time, an astonishing 89,500 American soldiers were either killed, injured or captured while fighting in the Battle of the Bulge; an action vividly recreated for television in 2001 by Steven Spielberg in the mini-series Band of Brothers.
The Battle of the Bulge formed part of the Ardennes counteroffensive by the Germans - hard and violent fighting in the dense, snow covered forests of Belgium and Luxemburg. It would turn out to be the last major offensive of the war by the Germans on the Western Front.
It was no knife thrust through the fields, but rather a grinding of a drill, inch by inch forward.
However, the Axis’ focus was hampered by what Dr Johnston described as the “relentless” advancement by Russian forces to the East of Germany, so strong in fact that the Germans even pleaded with British and American allies to agree to a partial surrender so that they could refocus their forces against the Russians in the East of the European continent.
“Of course, what is happening and what is benefiting western allies is the Russians’ relentless advance from the East. That is just a pretty much unstoppable machine."
Dr Johnston added:
“And actually, there are several instances where the Germans probably try and make a separate peace with the western allies, in places like Italy.
“But the allies are united in this and make it clear, they will only accept the total surrender of the German state.”
The allies did finally cross the Rhine in March 1945, but, according to Dr Johnstone, that didn’t mean the ferocity of the fighting gave up.
“Once they are across the Rhine in March 1945, they begin this advance through the towns and cities of North West Germany, on the British axis of advance. Some of these towns are captured relatively easily, some of them are really held on to and have to be reduced to rubble.
“Osnabruck, for example, is severely damaged in the fighting. There is a fairly relentless advance by the British taking place, but they are still taking casualties. It’s certainly no easy procession. There is this sense of, well who will get to Berlin first; will it be the allies, or will it be the Russians?”
The war in Europe was moving to its conclusion. And as it did, thoughts about what would happen next began to occupy the minds, not only of world leaders like Churchill and Stalin, but also of the soldiers fighting through the German towns and cities.
Would the end of the war translate into the returning home of thousands of soldiers? What would a defeated Germany look like in post war years and who would control it anyway? And what of the war in the Far East with Japan? All these questions needed answers.
But first, the Germans had to be beaten, and as April 1945 began, the climax of this long, bloody war approached. The Battle for Berlin commenced.