The First World War

1914: the heir to the Austrian throne was assassinated by a serbian student in Sarajevo

So, Austria declared war on Serbia and France went to Serbia's aid.

When Germany invaded Belgium to attack France, Britain attacked Austria and Germany.

1915: Italy entered the war with the Triple Entente.

In the first years of the 19th century there were many contrasts between nations due to economic interests.

For this reason, in Europe, two opposite alliances formed:

1919: the victorious nations took part in a post-war summit in Paris.

1918: Germany was defeated leaving the world in the chaos.

1917: because of the Bolshevik Revolution Russia retreated but the U.S. entered the war supporting of the Allied Forces.