On March 21, 1918, Germany launched Operation Michael, the first of the Spring Offensives, with a five-hour artillery bombardment of unprecedented intensity followed by an infantry assault along a 60-mile stretch of the Western Front. Using new stormtrooper infiltration tactics, German forces achieved the war's most dramatic advance in years, driving British forces back nearly 40 miles, but the offensive ultimately stalled from exhaustion and supply failures, and Germany never regained the initiative.
By March 1918, Germany faced a closing window: Russia had exited the war after the Bolshevik Revolution, freeing up roughly 50 divisions for the Western Front, but American troops were arriving in France at a rate that would soon overwhelm any temporary German advantage. General Erich Ludendorff gambled everything on a knockout blow before the Americans could tip the balance decisively.
At 4:40 AM on March 21, roughly 6,000 German guns opened fire on British positions along the Somme sector, firing over a million shells in five hours, mixing high explosive with poison gas in one of the war's most concentrated bombardments. Specially trained stormtrooper units then infiltrated through weak points in British lines, bypassing strongpoints rather than attacking them head-on, a tactical innovation that produced stunning early gains: by nightfall German forces had advanced further than either side had managed in three years of trench warfare.
Within days German troops had pushed the British Fifth Army back nearly 40 miles, threatening to split British and French forces entirely. But the advance outran its supply lines, exhausted infantry could not exploit their own breakthroughs, and Allied reserves, including fresh American units, eventually stabilized the front. The offensive cost Germany roughly 240,000 irreplaceable casualties, and by summer the exhausted German army faced the war-winning Allied counteroffensives of 1918.