The WW1 Battle Location Ypres (5 letters) was a Belgian city that was the site of three major battles during World War I. The first battle, known as the First Battle of Ypres, was fought in October and November 1914 and was the last major battle of the war's 'Race to the Sea'. The Second Battle of Ypres was fought in April and May 1915 and was the first major use of poison gas on the Western Front. The Third Battle of Ypres, also known as the Battle of Passchendaele, was fought from July to November 1917 and was one of the bloodiest battles of the war.