The line of fighting in World War I that stretched from the Vosges mountains through Amiens in France to Ostend in Belgium. Fighting in World War I began in August 1914 when German forces, adopting the Schlieffen Plan to fight on two fronts by first swiftly neutralizing France, were checked in the first Battle of the Marne. The subsequent German attempt to reach the Channel ports was defeated in the first Battle of Ypres (12 October–11 November). Thereafter both sides settled down to trench warfare, the distinctive feature of fighting on this front. The year 1915 saw inconclusive battles with heavy casualties: Neuve Chapelle (March), the second Battle of Ypres (April/May), when poison gas was used for the first time, and Loos (September). In 1916 Germany’s heavy attack on Verdun nearly destroyed the French army but failed to secure a breakthrough. To relieve pressure on the French, the British bore the brunt of the Somme offensive (July), gaining little ground and suffering appalling casualties. Early in 1917 the Germans withdrew to a new set of prepared trenches, the Siegfried Line (or Hindenburg Line), and in 1917 the Canadians captured Vimy Ridge. In November the British launched yet another major offensive, the Battle of Passchendaele (or third Battle of Ypres), and lost 300,000. The entry of the USA into the war (1917) meant that the Allies could draw on its considerable resources. US troops commanded by General Pershing landed in France in June 1917. In March 1918 Ludendorff’s final offensive began, with his troops again reaching the Marne before being stemmed by US forces at Château‐Thierry. Foch, now Allied commander‐in‐chief, began the counter‐offensive with the third Battle of the Marne (July). British troops broke the Siegfried Line near St Quentin, while the Americans attacked through the Argonne region. By October Germany’s resources were exhausted and on 11 November Germany signed the armistice that marked the end of World War I.