World War I, or the Great War, was a conflict based largely in Europe. It ran between 1914 and 1918. It began after the assassination of Archduke Franz Ferdinand and the Austro-Hungarian invasion of Serbia on the 28th July.
The war is seen as one of the most important in history and the mark at which the German Empire overtook the British and French.
The main treaties that ended the war were the Treaty of Paris and the Treaty of Brest-Litovsk.