Bulgaria By ExecutiveCouncil Oct 11, 1915 Bulgaria declared war on Serbia because the Central Powers could offer them territory that they wanted. Oct 14, 1915 The Bulgarian army had come betweeen the Allies and the Serbian army, effectively blocking them. Apr 27, 1917 Bulgarians hold off British attacks. The Bulgarian army clearly had an advantage. Sep 14, 1918 Bulgarian army mutinied and deserted because of heavy losses of troops. Sep 28, 1918 Bulgaria began to discuss an armistice with the Allies Nov 27, 1919 Bulgaria signed the Treaty of Treaty of Neuilly-sur-Seine. This treaty imposed harsh punishments on teh Bulgarians like the Germans.