Second Battle of the Marne

A major Allied victory over German forces in northeastern France in July–August 1918, it ended Germany’s last major offensive on the Western Front and began the Allies’ sustained advance.

German Spring Offensive: A series of German offensives on the Western Front in 1918, launched before American forces could arrive in strength. The Marne offensive was the final phase of Germany’s attempt to win the war before U.S. manpower tipped the balance.
Operation Michael: The first and largest German offensive of the 1918 Spring Offensive, launched in March against British forces. Its gains and costs shaped Germany’s later attempts to break Allied lines.
Erich Ludendorff: German general and chief military strategist who directed Germany’s 1918 offensives. Ludendorff ordered the July attack despite the risks of extending German forces.
Hundred Days Offensive: The Allied series of offensives from August to November 1918 that drove German forces back and ended World War I. The Marne victory set the stage for the sustained Allied attacks that followed.
Ferdinand Foch: French general who became supreme commander of Allied forces on the Western Front in 1918. Foch coordinated Allied reserves and counterattacks after the German advance stalled.
Third Battle of the Aisne: A German offensive in May 1918 that crossed the Aisne River and advanced toward the Marne. Its success created the salient from which Germany launched the July offensive.
Émile Fayolle: French general who commanded the French Tenth Army during the Allied counteroffensive in July 1918. Fayolle led the Tenth Army’s attack against the western side of the German salient.
Battle of Amiens: An Allied attack launched on August 8, 1918, that began the Hundred Days Offensive with a major breakthrough. Amiens followed the Marne and demonstrated the Allies’ growing ability to combine arms and surprise.
Château-Thierry: A town on the Marne River in northeastern France, captured by German forces in May 1918 and retaken by the Allies in July. Its recapture helped secure the western flank of the German salient.
Operation Gneisenau: A German offensive in June 1918 intended to improve positions near the Aisne before a larger attack. It expanded German positions ahead of the final Marne offensive.

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Meuse–Argonne offensiveRelated: Its outcome shifted the initiative to the Allies before the autumn offensives.