Ypres is a town in West Flanders, Belguim approximately 25 miles south of Ostend.  It was the site of 3 major battles between 1914 and 1917.

The 1st battle took place between October and November 1914 when a British offensive aimed at securing the Channel ports of Dunkirk and Ostend clashed with a German offensive that was aiming to do the same thing.  The subsequent fighting was extremely heavy and ended with the Germans gaining Messines Ridge and other commanding ground but with the British and French holding a salient (a piece of land or section of fortification that juts out to form an angle) around Ypres extending into the German line.  The British and French losses were estimated at 150,000 men, the German losses were about the same.

The following link takes you to the description of the battle on Wikipedia.  Other descriptions of this battle can be found by clicking on the following links.

Great War  First World War  History  History Learning Site