The son of a soldier, General Jean Blanchard served in the Great War in the Artillery and by 1918 was Colonel on General Joffre's staff. He is one of the twelve generals, who make up the French Higher War Council, and on the outbreak of war was, given command of the French 1st Army. Later he assumed command of the Allied Armies of the North East, and for his brilliant conduct of the Battle of Flanders was awarded on June 3 the Grand Cross of the Legion of Honour.