One French tank slaughtered a German Panzer company

For France, the hostilities technically began in September, 1939, when they declared war on Germany after the invasion of Poland. But September to the following May is referred to as the "Phony War" because of the small amount of fighting that actually happened.

There were some battles, though, including a 1939 armored advance past the Maginot Line where some of France's newest tanks, B1 Chars, proved themselves to be nearly invincible. They had thick, sloped armor over their entire body and a turret which German tanks simply had no means of penetrating — except at point-blank range.

The foray past the Maginot Line was short-lived, however. Not all of the French forces were impervious to damage, and the generals saw an attack against massed German forces as a waste of men and resources while the war was so limited.