Operation Barbarossa June 22,1941
The start of Hitler's fall from power can be argued too many different points in his timeline, what cannot be argued is how damaged his political and power structure became after the failed Operation Barbarossa and the eventual counter invasion by Russia. Hitler sat poised to control most of eastern Europe for the foreseeable future while many thinking his outright domination of Europe as a whole was not unrealistic. Hitler's alliance with Stalin, the German-Soviet Pact, was beneficial to both Nations and allowed Germany to fight the Western Allies with all of his focus and military might, there was no need to build up the eastern front because Stalin was not going to invade Germany anytime soon, as Stalin was dependent upon Germany for its armament shipments.
Normandy Invasion June 6,1944
After Hitler broke the German-Soviet pact with Stalin, Russia made alliances with Britain, France and the United States, now making the Allied Forces considerably stronger. Stalin pushed the Allied Forces to commit to attacking Germany from the Western Front with a cross channel invasion from Britain to Germany controlled France. The Allied forces initiated the Normandy Invasion in June of 1944, landing and taking control of the beach, giving the Allied Forces a major foothold in mainland Europe for the first time in the War. The allied liberation force was not slowed, and by August 25, 1944 they had liberated France after four years under German occupation. By Dec 16, 1944, they had pushed back the German front line back to the Ardennes region of Belgium and Luxembourg, at which point Hitler launched his last counter offensive of the Western Campaign, the Battle of the Bulge lasted a little more than 5 weeks and only caught the allied forces off guard, because of their sheer exhaustion from pushing back the German front line so fast.
Hitlers Bunker January 1945
Hitler never having been able to admit mistakes or take full or even partial blame for his poor choices, his last days were no different from his life. Hitler knew the end was coming, so he went to the protection of his hardened battle bunker in January of 1945. From here, Hitler was updated daily on the advancement of not only the Allied Forces coming from the west. but the menacing Red Army coming from the east, time was no longer on Hitler's side. Knowing the end was near, one of Hitler's last commands, which was not followed by Albert Speer, was issuing the Nero Decree on March 19, 1945. The order would be the total destruction of all of Germany infrastructure, leaving the remaining German people to live in Stone Age conditions, for their failure to not have the will and drive that Hitler himself had, keeping in mind, that Hitler would commit suicide just 42 days after issuing this order.
Hitlers Death
Hitler committed suicide on April 30,1945 alongside his wife of two days Eva Braun. The American Forces were within fifty miles of Berlin while the Russian Forces were already on the outskirts of Berlin and were within two days of reaching and taking control of the bunker.