Verdun was the strongest point in pre-war France, ringed by a string of powerful forts, including Douaumont and Fort Vaux. By 1916, the salient at Verdun jutted into the German lines and lay vulnerable to attack from three sides. The historic city of Verdun had been an oppidum of the Gauls before Roman times and later a key asset in wars against Prussia, and Falkenhayn suspected that the French would throw as many men as necessary into its defence. Ironically, France had substantially weakened Verdun's defences after the outbreak of the war, an oversight that would contribute to the removal of Joseph Joffre from supreme command at the end of 1916. The attack was slated to begin on 12 February, then 16 February, but the snow forced repeated postponements.