Question: On what date did the German offensive of which the First Battle of Villers-Bretonneux was a part begin?
Sentence (from "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.
Relevant evidence: Yes