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).
Cassel, Nord Cassel (from Flemish; "Kassel" in modern Dutch spelling) is a commune in the Nord départment in northern France. Built on a prominent hill overlooking French Flanders, the town has existed since Roman times. It was developed by the Romans into an important urban centre and was the focus of a network of roads, which are still in use today, that converge on the hill. After the fall of the Roman Empire, Cassel became an important fortified stronghold for the rulers of Flanders which was repeatedly fought over before finally being annexed to France in the 17th century. It was the headquarters of Marshal Ferdinand Foch during part of the First World War. In 1940, during the German invasion of France, Cassel was the scene of a fierce three-day battle between British and German forces which resulted in much of the town being destroyed.