Major German military offensive during the First World War that began the Spring Offensive on 21 March 1918. It was launched from the Hindenburg Line, in the vicinity of Saint-Quentin, France. Its goal was to break through the Allied (Entente) lines and advance in a north-westerly direction to seize the Channel ports, which supplied the British Expeditionary Force (BEF) and to drive the BEF into the sea. Two days later General Ludendorff, the Chief of the German General Staff, changed his plan and pushed for an offensive due west, along the whole of the British front north of the River Somme. This was designed to separate the French and British Armies and crush the British forces by pushing them into the sea. The offensive ended at Villers-Bretonneux, to the east of the Allied communications centre at Amiens, where the Allies managed to halt the German advance; the German Armies had suffered many casualties and were unable to maintain supplies to the advancing troops.