Causes of World War One

British people were keen to join up and fight in the First World War. Nobody imagined that it would last for four years and cost the lives of 3 million allied soldiers.

Britain had an alliance with France and Russia, called the Triple Entente (An alliance formed between the Britain, France, and Russia in 1907, which would lead to their partnership in the First World War).

Germany had a similar agreement with the Austro-Hungarian Empire and Italy. This was known as the Triple Alliance.

The Austro-Hungarian Archduke Franz Ferdinand was assassinated by a Serb called Gavrilo Princip, in the Bosnian capital Sarajevo on 28 June 1914. Angered by this, the Austro-Hungarian Empire declared war on Serbia.

Russia agreed to help Serbia. Germany agreed to help the Austro-Hungarian Empire by declaring war on Russia on 31 July 1914 and then on France.

Germany was keen to invade France before going on to fight Russia. Germany had a strategy to invade France, known as the Schlieffen Plan. This plan had been in place since 1897. The Germans thought that Russia would be the real danger and that they could easily defeat France within weeks.

This plan had one flaw: Germany needed to go through Belgium, a neutral country, to get to France. Britain warned Germany not to do this. Germany carried on with the Schlieffen Plan.

Britain declared war on Germany on 4 August 1914.