June 28 - Archduke Franz Ferdinand, heir to Austria-Hungary's throne, and his wife, Sophie, are assassinated by Serbian nationalist Gavrilo Princip while the couple were visiting Sarajevo.
Austria-Hungary declares war on Serbia
Austria-Hungary declares war on Serbia
Germany declares war on Russia.
Germany declares war on France.
The United Kingdom declares war on Germany, after Germany invades Belgium.
Germany declares a "war zone" around Great Britain
