The Battle of Tannenberg was of crucial importance in the first month of WWI.                                                                          

This is the secret story of The War to End All Wars. What happened when the first weapons of mass destruction reached the battlefield? We uncover this forgotten story of secret deals, government mistakes, and political intolerance.

April 1917: the most feared pilot of World War I is at the controls of the best fighter plane of the day. A 24-year-old legend at the top of his game, Manfred von Richthofen is up against a new generation of enemy aircraft.

America fought in World War One for just over nine months, and yet more people were killed there than were in the decade when we fought in Vietnam. Close to 120,000 Americans died, and we were a country forever changed.

Tanks were the first armored fighting machines to be used on the battlefield. These "land ships," as they were first called, were championed by Head of the British Admiralty, Winston Churchill. Adapted from an American tractor with caterpillar tracks.

The Germans, ignoring international treaties they signed, were first to weaponize a chemical. In this case it was chlorine--a highly toxic ingredient used in the manufacture of chemical dyes of which they had a huge supply.

While most people think the Blitz originated in WWII, the truth is that the first Blitz happened during WWI. Bombs were delivered from giant airships designed by Count Ferdinand von Zeppelin.

The Atlantic became a killing field as German submarines took on the might of the dominant British Navy. The stealth and silent killers were able to sink 5,200 ships by war's end, and nearly brought Britain to its knees.