For the past two years, Entente armies have remained inactive at Salonika, where the Allies' politically ambitious but militarily ineffective commander in chief, General Sarrail, had been replaced at the end of 1917 by General Guillaumat, who had in turn been succeeded in July 1918 by General L.-F.-F. Franchet d'Esperey.

Now that the Central Powers have begun to disintegrate, D'Esperey launches a major offensive in September with six Serbian and two French divisions against a seven-mile front held by only one Bulgarian division, which is thoroughly demoralized by antiwar propaganda and harsh conditions.