Facts about World War 1 and 2

The secret tunnelers of WW1

World War One often conjures up images of a horrific bloodbath fought in the trenches of the Western Front. While this certainly captures some of the reality, did you know that the war spread as far as China? Or that it was fought by servicemen from Asia, North America, the Caribbean, Australasia and Africa?

Here are 12 surprising facts about World War One that you probably didn't know.

1. An explosion on the battlefield in France was heard in London

While the war raged on in the mud and trenches, a very different war was taking place beneath the soldiers' feet. A group of miners, operating in total secrecy, dug tunnels up to 100ft underground, to plant and detonate mines beneath the enemy's trenches. Their biggest success was at Messines Ridge in Belgium where over 900, 000lbs of explosives were simultaneously detonated in 19 underground tunnels. Much of the German front line was destroyed, and the explosions were heard 140 miles away by the British prime minister in Downing St.

Is there a historian in you?

For new perspectives on World War One, the BBC has teamed up with UK universities to offer free online courses.

2. Journalists faced execution

A handful of journalists risked their lives to report on the realities of war. As the Government sought to control the flow of information from the frontline at the start of the war, journalists were banned. Reporting on the conflict was, in the opinion of the War Office, helping the enemy. If caught, they faced the death penalty.

3. 12 million letters were delivered to the front every week

Astonishingly, it only took two days for a letter from Britain to reach the front in France. The journey began at a purpose-built sorting depot in Regent's Park before being shipped to the trenches. By the end of the war, two billion letters and 114 million parcels had had been delivered.

Not just mud and trenches

4. War work turned some women's skin yellow

When a generation of men went to fight the war, more than a million women took their place in the workforce. They worked long hours, often in poor conditions and with dangerous chemicals. The so-called 'canaries' were women who worked with TNT, which gave them toxic jaundice and turned their skin yellow.

5. WW1 sparked the invention of plastic surgery