22 June 1941 - Operation Barbarossa

On June 22 1941 the forces of Nazi Germany attacked the Soviet Union. This was the largest land campaign in history and casualties on both sides number in the tens of millions.

Some interesting aspects of the German invasion:

1). Was Stalin a fool who refused to believe that Hitler would attack him or was the situation more complex?

See German disinformation operations - Barbarossa 1941.

2). Were Soviet codes impregnable?

See Compromise of Soviet codes in WWII.

3). Were the German shocked by the performance of the new Soviet tanks like the T-34?

See WWII Myths - T-34 Best Tank of the war.

4). Some statistics on German and Soviet losses:

Strength and loss data Eastern Front – part 1

Eastern Front Aircraft Strength and Losses 1941-45

Tank strength and losses – Eastern Front