Operation Barbarossa was the largest invasion in history. Almost 3.5 million men smashed into Stalin's Red Army, reaching the gates of Leningrad, Moscow, and Sevastopol. But not all of this vast army was German; by the summer of 1942, over 500,000 were Romanians, Italians, Hungarians, Slovaks, and Croatians--Hitler's Axis allies. As part of the German offensive that year, more than four allied armies advanced to the Don, only to be annihilated in the Red Army's Saturn and Uranus winter offensives. Hundreds of thousands were killed, wounded, or captured, and the German Sixth Army was left...

The battle in which the destruction of the shield wall changed Western Europe forever.

In 1066, a foreign invader won the throne of England in a single battle and changed not only the history of the British Isles but of Christendom forever. Harold Godwinson's army, exhausted from their victory against an invading Norwegian Viking army at the Battle of Stamford Bridge in the north, and his navy, scattered by storms, could not hold back William of Normandy. But would the invasion have succeeded if the two armies had met on equal terms?

Author and ex-Captain in the...