<Table> <Tr> <Th> Date </Th> <Th> Declarer </Th> <Th> On </Th> </Tr> <Tr> <Th colspan="3"> 1914 </Th> </Tr> <Tr> <Td> July 28 </Td> <Td> Austria - Hungary </Td> <Td> Serbia </Td> </Tr> <Tr> <Td> August 1 </Td> <Td> Germany </Td> <Td> Russia </Td> </Tr> <Tr> <Td> August 3 </Td> <Td> Germany </Td> <Td> France </Td> </Tr> <Tr> <Td> August 4 </Td> <Td> Germany </Td> <Td> Belgium </Td> </Tr> <Tr> <Td> United Kingdom </Td> <Td> Germany </Td> </Tr> <Tr> <Td> August 5 </Td> <Td> Montenegro </Td> <Td> Austria - Hungary </Td> </Tr> <Tr> <Td> August 6 </Td> <Td> Austria - Hungary </Td> <Td> Russia </Td> </Tr> <Tr> <Td> Serbia </Td> <Td> Germany </Td> </Tr> <Tr> <Td> August 9 </Td> <Td> Montenegro </Td> <Td> Germany </Td> </Tr> <Tr> <Td> August 11 </Td> <Td> France </Td> <Td> Austria - Hungary </Td> </Tr> <Tr> <Td> August 12 </Td> <Td> United Kingdom </Td> <Td> Austria - Hungary </Td> </Tr> <Tr> <Td> August 22 </Td> <Td> Austria - Hungary </Td> <Td> Belgium </Td> </Tr> <Tr> <Td> August 23 </Td> <Td> Japan </Td> <Td> Germany </Td> </Tr> <Tr> <Td> August 25 </Td> <Td> Japan </Td> <Td> Austria - Hungary </Td> </Tr> <Tr> <Td> November 1 </Td> <Td> Russia </Td> <Td> Ottoman Empire </Td> </Tr> <Tr> <Td> November 2 </Td> <Td> Serbia </Td> <Td> Ottoman Empire </Td> </Tr> <Tr> <Td> November 3 </Td> <Td> Montenegro </Td> <Td> Ottoman Empire </Td> </Tr> <Tr> <Td> November 5 </Td> <Td> United Kingdom France </Td> <Td> Ottoman Empire </Td> </Tr> <Tr> <Th colspan="3"> 1915 </Th> </Tr> <Tr> <Td> May 23 </Td> <Td> Italy </Td> <Td> Austria - Hungary </Td> </Tr> <Tr> <Td> August 21 </Td> <Td> Italy </Td> <Td> Ottoman Empire </Td> </Tr> <Tr> <Td> October 14 </Td> <Td> Bulgaria </Td> <Td> Serbia </Td> </Tr> <Tr> <Td> October 15 </Td> <Td> United Kingdom Montenegro </Td> <Td> Bulgaria </Td> </Tr> <Tr> <Td> October 16 </Td> <Td> France </Td> <Td> Bulgaria </Td> </Tr> <Tr> <Td> October 19 </Td> <Td> Italy Russia </Td> <Td> Bulgaria </Td> </Tr> <Tr> <Th colspan="3"> 1916 </Th> </Tr> <Tr> <Td> March 9 </Td> <Td> Germany </Td> <Td> Portugal </Td> </Tr> <Tr> <Td> March 15 </Td> <Td> Austria - Hungary </Td> <Td> Portugal </Td> </Tr> <Tr> <Td> August 27 </Td> <Td> Romania </Td> <Td> Austria - Hungary </Td> </Tr> <Tr> <Td> Italy </Td> <Td> Germany </Td> </Tr> <Tr> <Td> August 28 </Td> <Td> Germany </Td> <Td> Romania </Td> </Tr> <Tr> <Td> August 30 </Td> <Td> Ottoman Empire </Td> <Td> Romania </Td> </Tr> <Tr> <Td> November 1 </Td> <Td> Bulgaria </Td> <Td> Romania </Td> </Tr> <Tr> <Th colspan="3"> 1917 </Th> </Tr> <Tr> <Td> April 6 </Td> <Td> United States </Td> <Td> Germany </Td> </Tr> <Tr> <Td> April 7 </Td> <Td> Cuba Panama </Td> <Td> Germany </Td> </Tr> <Tr> <Td> April 10 </Td> <Td> Bulgaria </Td> <Td> United States </Td> </Tr> <Tr> <Td> April 13 </Td> <Td> Bolivia </Td> <Td> Germany </Td> </Tr> <Tr> <Td> April 20 </Td> <Td> Ottoman Empire </Td> <Td> United States </Td> </Tr> <Tr> <Td> July 2 </Td> <Td> Greece </Td> <Td> Germany Austria - Hungary Ottoman Empire Bulgaria </Td> </Tr> <Tr> <Td> July 22 </Td> <Td> Siam </Td> <Td> Germany Austria - Hungary Ottoman Empire </Td> </Tr> <Tr> <Td> August 4 </Td> <Td> Liberia </Td> <Td> Germany </Td> </Tr> <Tr> <Td> August 14 </Td> <Td> China </Td> <Td> Germany Austria - Hungary </Td> </Tr> <Tr> <Td> October 6 </Td> <Td> Peru </Td> <Td> Germany </Td> </Tr> <Tr> <Td> October 7 </Td> <Td> Uruguay </Td> <Td> Germany </Td> </Tr> <Tr> <Td> October 26 </Td> <Td> Brazil </Td> <Td> Germany </Td> </Tr> <Tr> <Td> December 7 </Td> <Td> United States </Td> <Td> Austria - Hungary </Td> </Tr> <Tr> <Td> December 7 </Td> <Td> Ecuador </Td> <Td> Germany </Td> </Tr> <Tr> <Td> December 10 </Td> <Td> Panama </Td> <Td> Austria - Hungary </Td> </Tr> <Tr> <Td> December 16 </Td> <Td> Cuba </Td> <Td> Austria - Hungary </Td> </Tr> <Tr> <Th colspan="3"> 1918 </Th> </Tr> <Tr> <Td> April 23 </Td> <Td> Guatemala </Td> <Td> Germany </Td> </Tr> <Tr> <Td> May 8 </Td> <Td> Nicaragua </Td> <Td> Germany Austria - Hungary </Td> </Tr> <Tr> <Td> May 23 </Td> <Td> Costa Rica </Td> <Td> Germany </Td> </Tr> <Tr> <Td> July 12 </Td> <Td> Haiti </Td> <Td> Germany </Td> </Tr> <Tr> <Td> July 19 </Td> <Td> Honduras </Td> <Td> Germany </Td> </Tr> <Tr> <Td> November 10 </Td> <Td> Romania </Td> <Td> Germany </Td> </Tr> </Table>
<Table> <Tr> <Th> Date </Th> <Th> Declarer </Th> <Th> On </Th> </Tr> <Tr> <Th colspan="3"> 1914 </Th> </Tr> <Tr> <Td> July 28 </Td> <Td> Austria - Hungary </Td> <Td> Serbia </Td> </Tr> <Tr> <Td> August 1 </Td> <Td> Germany </Td> <Td> Russia </Td> </Tr> <Tr> <Td> August 3 </Td> <Td> Germany </Td> <Td> France </Td> </Tr> <Tr> <Td> August 4 </Td> <Td> Germany </Td> <Td> Belgium </Td> </Tr> <Tr> <Td> United Kingdom </Td> <Td> Germany </Td> </Tr> <Tr> <Td> August 5 </Td> <Td> Montenegro </Td> <Td> Austria - Hungary </Td> </Tr> <Tr> <Td> August 6 </Td> <Td> Austria - Hungary </Td> <Td> Russia </Td> </Tr> <Tr> <Td> Serbia </Td> <Td> Germany </Td> </Tr> <Tr> <Td> August 9 </Td> <Td> Montenegro </Td> <Td> Germany </Td> </Tr> <Tr> <Td> August 11 </Td> <Td> France </Td> <Td> Austria - Hungary </Td> </Tr> <Tr> <Td> August 12 </Td> <Td> United Kingdom </Td> <Td> Austria - Hungary </Td> </Tr> <Tr> <Td> August 22 </Td> <Td> Austria - Hungary </Td> <Td> Belgium </Td> </Tr> <Tr> <Td> August 23 </Td> <Td> Japan </Td> <Td> Germany </Td> </Tr> <Tr> <Td> August 25 </Td> <Td> Japan </Td> <Td> Austria - Hungary </Td> </Tr> <Tr> <Td> November 1 </Td> <Td> Russia </Td> <Td> Ottoman Empire </Td> </Tr> <Tr> <Td> November 2 </Td> <Td> Serbia </Td> <Td> Ottoman Empire </Td> </Tr> <Tr> <Td> November 3 </Td> <Td> Montenegro </Td> <Td> Ottoman Empire </Td> </Tr> <Tr> <Td> November 5 </Td> <Td> United Kingdom France </Td> <Td> Ottoman Empire </Td> </Tr> <Tr> <Th colspan="3"> 1915 </Th> </Tr> <Tr> <Td> May 23 </Td> <Td> Italy </Td> <Td> Austria - Hungary </Td> </Tr> <Tr> <Td> August 21 </Td> <Td> Italy </Td> <Td> Ottoman Empire </Td> </Tr> <Tr> <Td> October 14 </Td> <Td> Bulgaria </Td> <Td> Serbia </Td> </Tr> <Tr> <Td> October 15 </Td> <Td> United Kingdom Montenegro </Td> <Td> Bulgaria </Td> </Tr> <Tr> <Td> October 16 </Td> <Td> France </Td> <Td> Bulgaria </Td> </Tr> <Tr> <Td> October 19 </Td> <Td> Italy Russia </Td> <Td> Bulgaria </Td> </Tr> <Tr> <Th colspan="3"> 1916 </Th> </Tr> <Tr> <Td> March 9 </Td> <Td> Germany </Td> <Td> Portugal </Td> </Tr> <Tr> <Td> March 15 </Td> <Td> Austria - Hungary </Td> <Td> Portugal </Td> </Tr> <Tr> <Td> August 27 </Td> <Td> Romania </Td> <Td> Austria - Hungary </Td> </Tr> <Tr> <Td> Italy </Td> <Td> Germany </Td> </Tr> <Tr> <Td> August 28 </Td> <Td> Germany </Td> <Td> Romania </Td> </Tr> <Tr> <Td> August 30 </Td> <Td> Ottoman Empire </Td> <Td> Romania </Td> </Tr> <Tr> <Td> November 1 </Td> <Td> Bulgaria </Td> <Td> Romania </Td> </Tr> <Tr> <Th colspan="3"> 1917 </Th> </Tr> <Tr> <Td> April 6 </Td> <Td> United States </Td> <Td> Germany </Td> </Tr> <Tr> <Td> April 7 </Td> <Td> Cuba Panama </Td> <Td> Germany </Td> </Tr> <Tr> <Td> April 10 </Td> <Td> Bulgaria </Td> <Td> United States </Td> </Tr> <Tr> <Td> April 13 </Td> <Td> Bolivia </Td> <Td> Germany </Td> </Tr> <Tr> <Td> April 20 </Td> <Td> Ottoman Empire </Td> <Td> United States </Td> </Tr> <Tr> <Td> July 2 </Td> <Td> Greece </Td> <Td> Germany Austria - Hungary Ottoman Empire Bulgaria </Td> </Tr> <Tr> <Td> July 22 </Td> <Td> Siam </Td> <Td> Germany Austria - Hungary Ottoman Empire </Td> </Tr> <Tr> <Td> August 4 </Td> <Td> Liberia </Td> <Td> Germany </Td> </Tr> <Tr> <Td> August 14 </Td> <Td> China </Td> <Td> Germany Austria - Hungary </Td> </Tr> <Tr> <Td> October 6 </Td> <Td> Peru </Td> <Td> Germany </Td> </Tr> <Tr> <Td> October 7 </Td> <Td> Uruguay </Td> <Td> Germany </Td> </Tr> <Tr> <Td> October 26 </Td> <Td> Brazil </Td> <Td> Germany </Td> </Tr> <Tr> <Td> December 7 </Td> <Td> United States </Td> <Td> Austria - Hungary </Td> </Tr> <Tr> <Td> December 7 </Td> <Td> Ecuador </Td> <Td> Germany </Td> </Tr> <Tr> <Td> December 10 </Td> <Td> Panama </Td> <Td> Austria - Hungary </Td> </Tr> <Tr> <Td> December 16 </Td> <Td> Cuba </Td> <Td> Austria - Hungary </Td> </Tr> <Tr> <Th colspan="3"> 1918 </Th> </Tr> <Tr> <Td> April 23 </Td> <Td> Guatemala </Td> <Td> Germany </Td> </Tr> <Tr> <Td> May 8 </Td> <Td> Nicaragua </Td> <Td> Germany Austria - Hungary </Td> </Tr> <Tr> <Td> May 23 </Td> <Td> Costa Rica </Td> <Td> Germany </Td> </Tr> <Tr> <Td> July 12 </Td> <Td> Haiti </Td> <Td> Germany </Td> </Tr> <Tr> <Td> July 19 </Td> <Td> Honduras </Td> <Td> Germany </Td> </Tr> <Tr> <Td> November 10 </Td> <Td> Romania </Td> <Td> Germany </Td> </Tr> </Table>
who were the first two countries involved in world war 1
who were the first two countries involved in world war 1
Austria - Hungary Serbia
Austria - Hungary Serbia