August 8, 1914 - Britain enacts the Defense of the Realm Act (DORA) granting unprecedented powers to the government to control the economy and daily life. August 12, 1914 - Great Britain and France declare war on Austria-Hungary. Serbia is invaded by Austria-Hungary.August 17, 1914 - Russia invades Germany, attacking into East Prussia, forcing the outnumbered Germans there to fall back.ugust 8, 1914 - Britain enacts the Defense of the Realm Act (DORA) granting unprecedented powers to the government to control the economy and daily life. August 12, 1914 - Great Britain and France declare war on Austria-Hungary. Serbia is invaded by Austria-Hungary.