World War I (often abbreviated as WWI or WW1), also known as the First World War or the Great War, was a global war that lasted from 1914 to 1918. Contemporaneously described as "the war to end all wars", it led to the mobilisation of more than 70 million military personnel, including 60 million Europeans, making it one of the largest wars in history. It is also one of the deadliest conflicts in history, with an estimated 9 million combatant deaths and 13 million civilian deaths as a direct result of the war, while resulting genocides and the related 1918 influenza pandemic caused another 17–100 million deaths worldwide.
- 9 million combatants and 7 million civilians died as a result of WW1.
- The Spanish flu caused about a third of total military deaths in WW1.
- WW1 was the sixth deadliest conflict in world history.
- In 1917, Germany invited Mexicoto join WW1 by attacking the U.S. in order to recover the lost territories of Texas, New Mexico and Arizona.
- "He kept us out of war" was Woodrow Wilson' slogan for the 1916 election. About a month after he took office, the U.S. declared war on Germany.
- The WW1 ended at 11 o'clock in the morning of the 11th day of the 11th month of 1918.
- WW1 transformed the U.S. into the largest military power in the world.
- The room of a WW1 French soldier is still untouched since 1918.
- A WW1 homing pigeon saved 194 men by delivering a message despite losing a leg, an eye and having been shot through the chest.
- During WW1, a Hungarian man was shot in the frontal lobe, making it impossible for him to fall asleep. He continued to live a full, sleepless life.
- Chemotherapy is a by-product of the mustard gas used in WW1.
- After World War I, there were so few men in Germany that only 1 in 3 women would find a husband.
- Nearly 13,000 Native Americans fought during World War I, despite not having a U.S. citizenship.
- Four empires collapsed after WWI: Ottoman, Austro-Hungarian, German, and Russian.
- After WW1, Finland, Estonia, Latvia, Lithuania, and Poland emerged as independent nations.
- During WW1, a British soldier spared the life of a wounded German: Adolf Hitler.
- The youngest soldier to serve during WW1 was only 8 years old.
- Germany made its final reparations payment from the WW1 Treaty of Versailles in 2010.
- British soldiers in WW1 had a tea ration of six pints a day.
- Dogs were used as messengers in WW1, carrying orders to the front lines in capsules attached to their bodies.
- During WW1, the U.S. Government tried to rename hamburgers as "liberty sandwiches" to promote patriotism.
- During WW1, the Belgian King personally led the army, the Queen served as a nurse, and the 14-year-old Prince enlisted as a private.
- During WW1, the King of England, the Tsar of Russia, and the Emperor of Germany were all first cousins.
- The German WW1 officer that recommended Hitler for an Iron Cross was Jewish. He was later arrested, then released by the SS once they discovered his identity.
- Spain was neutral in WW1 and WW2, but experienced a civil war (1936-1939) which killed over 500,000 people.
- A British prisoner of war, captured by the Germans in WW1, was freed to see his dying mother, then went back to the prison camp because he gave the Kaiser 'his word' he would return.
- WW1 allied soldiers would fire thousands of rounds at random over the German trenches to boil the water in their machine guns to make tea.
- Germany's debt from WW1 was equivalent to 96,000 tons of gold.
- During WW1, Marie Curie attempted to donate her Gold Nobel Prize medals for the war effort but the French National Bank refused to accept them.
- The last surviving WW1 Veteran was a woman.
- She was a waitress at an air base.
- During WW1, a lone Portuguese soldier convinced the Germans that they were fighting against an entire unit.
- Teddy Roosevelt volunteered for service in World War I ten years after having served as U.S. president.
- Anne Frank's father was an officer in the German army during World War I.
- One of the assassins of Archduke Franz Ferdinand threw a grenade but missed the car. He swallowed cyanide and jumped to the River Miljacka. The cyanide was expired and did not work, and the river was only 10cm deep.
- He was captured seconds later.
- During WW1, New Zealand raised an army of 100,000 men, about 10% of its population.
- During the World War I, the British Army attempted to train seagulls to poo on the periscopes of enemy submarines.
- Germany was the first country ever to implement Daylight Saving Time in order to save energy during WW1.
- The use of chemical weapons such as mustard gas resulted in more than 1.3 million casualties during WW1.
- The first and last British soldiers that died in WW1 are, by coincidence, buried 15 feet away from each other.
- Over 8 million horses died in WW1. Of those who survived, most were sent to Belgian butchers, being regarded as unfit for any other purpose.
- During WW1, the Ottoman Empire slaughtered over 1.5 million Armenians. It gave origin to the word "Genocide", although it is not officially recognized as such by most countries.
- Houdini drew on his arsenal of magician's tricks to provide special instructions to American troops during WWI.
- It's estimated that the Allied troops brought home 1.5 million cases of syphilis and gonorrhea from World War I.
- The most decorated American WW1 veteran from Texas was an undocumented Mexican immigrant named Marcelino Serna.
- The name "The First World War" was used as early as 1918, by a journalist who felt it would not be the last.
- There's a monument to honour the almost 1 million Allied horses who died during WW1.
- During the First World War, 1,000 double-decker London buses, complete with drivers and mechanics, were sent to the front line.
- During WWI, a group of Russian and German soldiers agreed to a cease-fire to fend off an attack by wolves.