Battle of Ypres
After the Third Battle of Ypres, the Ypres Salient was left relatively quiet until the Fourth Battle of Ypres (Battle of the Lys), when the German spring offensive threatened to overwhelm the area. This offensive was stopped at the point the Allies were closest to being forced to abandon the salient. By August 1918, the Fifth Battle of Ypres (part of the Hundred Days Offensive) pushed the German forces out of the salient entirely and they did not return.