1914    Franz Ferdinand, Archduke of Austria and his wife Sophie are assassinated in Sarajevo by young Serbian nationalist Gavrilo Princip, the ''casus belli'' of World War I.

1914    World War I: Austria-Hungary declares war on Serbia after Serbia rejects the conditions of an ultimatum sent by Austria on July 23 following the assassination of Archduke Francis Ferdinand.

1914    Germany declares war on Russia at the opening of World War I. The Swiss Army mobilises because of World War I

1914    Germany declares war on Russia at the opening of World War I. The Swiss Army mobilises because of World War I

1914    World War I: Germany declares war against France.

1914    World War I: Germany invades Belgium. In response, the United Kingdom declares war on Germany. The United States declare their neutrality.

1914    World War I: the German minelayer ''Königin Luise'' lays a minefield about 40 miles of the Thames Estuary (Lowestoft). She is intercepted and sunk by the British light-cruiser ''HMS Amphion''.

1914    World War I: World War I: World War I: [[First Battle of the Atlantic

1914    World War I: the United Kingdom declares war on Austria-Hungary; the countries of the British Empire follow suit.

1914    World War I: Battle of Cer begins.