The Battle of the Lys, also known as the Fourth Battle of Ypres, was fought from 7 to 29 April 1918 and was part of the German spring offensive in Flanders during the First World War. It was originally planned by General Erich Ludendorff as Operation George but was reduced to Operation Georgette, with the objective of capturing Ypres, forcing the British forces back to the Channel ports and out of the war. In planning, execution and effects, Georgette was similar to (although smaller than) Operation Michael, earlier in the Spring Offensive.