Born in 1851 Foch had already secured his reputation before the War as a soldier and  military theorist.   Foch's prestige soared as a result of the victory at the Marne, for which he was widely credited as a chief actor while commanding the French Ninth Army. He was then promoted again to command Army Group North, in which role he was required to cooperate with the British forces at Ypres and the Somme.  Appointed Chief of the General Staff in 1917, Foch was ultimately appointed "Commander-in-Chief (Generalissimo) of the Allied Armies" in the spring of 1918. He played a decisive role in halting a renewed German advance on Paris in the Second Battle of the Marne, after which he was promoted to Marshal of France.

On 11 November 1918 Foch accepted the German request for an armistice. Foch advocated peace terms that would make Germany unable to pose a threat to France ever again. After the Treaty of Versailles, because Germany was allowed to remain a united country, Foch declared "This is not a peace. It is an armistice for twenty years". His words proved, sadly,  prophetic.