Operation Michael — German Spring Offensive Begins

Germany launched Operation Michael, the first of a series of massive Spring Offensives (Kaiserschlacht—'Kaiser's Battle') using new stormtrooper infiltration tactics to achieve a decisive breakthrough before American forces could arrive in strength. On the first day, Germany fired 1.16 million shells in 5 hours. The offensive advanced up to 65 km—the largest territorial gain on the Western Front since 1914—but failed to achieve strategic objectives and exhausted Germany's best shock troops.