On what date did the German offensive of which the First Battle of Villers-Bretonneux was a part begin?
Spring Offensive The 1918 Spring Offensive or Kaiserschlacht ("Kaiser's Battle"), also known as the Ludendorff Offensive, was a series of German attacks along the Western Front during the First World War, beginning on 21 March 1918, which marked the deepest advances by either side since 1914. The Germans had realised that their only remaining chance of victory was to defeat the Allies before the overwhelming human and matériel resources of the United States could be fully deployed. They also had the temporary advantage in numbers afforded by the nearly 50 divisions freed by the Russian surrender (the Treaty of Brest-Litovsk).
Lochnagar mine The Lochnagar mine was an underground explosive charge, secretly planted by the British during the First World War, ready for 1 July 1916, the first day on the Somme. The mine was dug by the Tunnelling Companies of the Royal Engineers under a German field fortification known as "Schwabenhöhe" (Swabian Height) in the front line, south of the village of La Boisselle in the Somme "département". The British named the mine after Lochnagar Street, the British trench from which the gallery was driven. The charge at Lochnagar was one of 19 mines that were placed beneath the German lines on the British section of the Somme front, to assist the infantry advance at the start of the battle. The Lochnagar mine was sprung at 7:28 a.m. on 1 July 1916 and left a crater 30 m deep and 100 m wide, which was captured and held by British troops. The attack on either flank was defeated by German small-arms and artillery fire, except on the extreme right flank and just south of La Boisselle, north of the Lochnagar Crater. The crater has been preserved as a memorial and a religious service is held each 1 July.