Battle of Passchendaele

The Third Battle of Ypres, also known as the Battle of Passchendaele, was a campaign of the First World War, fought by the Allies against the German Empire. The battle took place on the Western Front, from July to November 1917, for control of the ridges south and east of the Belgian city of Ypres in West Flanders, as part of a strategy decided by the Allies at conferences in November 1916 and May 1917. Passchendaele lies on the last ridge east of Ypres, 5 mi from Roulers, a junction of the Bruges--to-Kortrijk railway. The station at Roulers was on the main supply route of the German 4th Army. Once Passchendaele Ridge had been captured, the Allied advance was to continue to a line from Thourout to Couckelaere.

Further operations and a British supporting attack along the Belgian coast from Nieuport, combined with an amphibious landing, were to have reached Bruges and then the Dutch frontier.

Source: Wikipedia