1. World War 1 was a military conflict lasting from 1914 to 1918 which involved nearly all the biggest powers of the world. It involved two opposing alliances - the Allies and the Central Powers. The countries of the Allies included Russia, France, British Empire, Italy, United States, Japan, Rumania, Serbia, Belgium, Greece, Portugal and Montenegro. The countries of the Central Powers included Germany, Austria-Hungary, Turkey and Bulgaria.
2. World War 1 was triggered on 28 June 1914 by the assassination of the Archduke Franz Ferdinand of Austria and his pregnant wife Sophie. Archduke Franz Ferdinand of Austria was the nephew of Emperor Franz Josef and heir to the throne of Austria and Hungary. The assassination was planned by a Serbian terrorist group, called The Black Hand and the man who shot Franz Ferdinand and his wife was a Bosnian revolutionary named Gavrilo Princip
3 . The war had many causes:
a) a tangle of alliances made between countries, to maintain a balance power in Europe, which brought about the scale of the conflict
b) the Bosnian Crisis where Austria-Hungary took over the former Turkish province of Bosnia in 1909 angering Serbia.
c) countries were building their military forces, arms and battleships
d) countries wanted to regain lost territories from previous conflicts and build empires
e) the Moroccan Crisis where Germans were protesting in 1911 against the French possession of Morocco
4. Other names for World War 1 include 'The War to End All Wars', The War of the Nations and 'The Great War'.