The Macedonian front stayed mostly stable throughout the war. In May 1918, Greek forces attacked Bulgarian forces and defeated them at the Battle of Skra-di-Legen on 30 May 1918. Later in 1918, the Allied forces drove their offensive from Greece into occupied Serbia. In September of that year, Allied forces (French, Greek, Serb, Italian, and British troops), under the command of French General Louis Franchet d'Espèrey, broke through German, Austro-Hungarian, and Bulgarian forces along the Macedonian front. Bulgaria later signed the Armistice of Salonica with the Allies in Thessaloniki on 29 September 1918. By October, the Allies. including the Greeks under French General Louis Franchet d'Espèrey. had taken back all of Serbia and were ready to invade Hungary until the Hungarian authorities offered surrender.