Also often called the First World War or The Great War, here is Newsround's guide to what happened during World War One, a global conflict that started 110 years ago.

Discover how country alliances led to World War One and why the great war started in this BBC Bitesize history KS2 guide.

World War One And The 'Short-War Illusion' Despite the final horrific death toll, many believed war in Europe would be over in months, writes a leading historian. By Professor David Stevenson ...

One by one, the core principles of the Bismarckian system had collapsed: Britain had abandoned its historic neutrality to join an anti-German alliance and had reconciled with Russia, its great ...

On April 6, 1917, the United States entered World War I. For three years before, activists and legislators had urged lawmakers not to join this unprecedented “war to end all wars,” and their ...

Royal cousins Wilhelm II and King George V went to war As nations gear up to mark 100 years since the start of World War One, academic argument still rages over which country was to blame for the ...