When and how did Hitler invade Union ?

Explanation

By the end 1940, Hitler was at the pinnacle of his power and now he moved towards Eastern Europe after defeating France in the west, he attacked the Soviet Union in June 1941. In this historic blunder, Hitler exposed the German western front to British aerial bombing and the eastern front to the powerful Soviet armies. The Soviet Red Army inflicted a crushing and humiliating defeat on Germany at Stalingrad. After this, the Soviet Red Army hounded out the retreating German soldiers until they reached the heart of Berlin, establishing Soviet power over the entire Europe for half for half a century thereafter.