The Fifth Battle of Ypres, also called the Advance of Flanders and the Battle of the Peaks of Flanders (French: Bataille des Crêtes de Flandres) is an informal name used to identify a series of battles in northern France and southern Belgium from late September through October 1918.

Background

After the German Spring Offensive of 1918 was stopped, German morale waned and the increasing numbers of American soldiers arriving on the Western Front gave the Allies a growing advantage over the German forces. To take advantage of this Marshal Ferdinand Foch developed a strategy which became known as the Grand Offensive in which attacks were made on the German lines over as wide a front as possible. Belgian, British and French forces around the Ypres Salient were to form the northern pincer of an offensive towards the Belgian city of Liège. The British Second Army had followed up some minor withdrawals and had fought the Action Outtersteene Ridge on 18 August, after which the front had become quiet, resulting in Allied troops in the area being well-rested by late September.

The Battle of Ypres was during the First World War, in the general area of the Belgian city of Ypres, where the German and the Allied armies (Belgian, French, British Expeditionary Force (B.E.F.) and Canadian Expeditionary Force (C.E.F.)) clashed. There were hundreds of thousands of casualties. The term "Battle of Ypres" could mean all the fighting that occurred in that area. But the "Battle of Ypres" could refer more specifically to any one of five battles which have been separately identified and named (and which themselves can be subdivided into smaller named battles).

The five battles were: