Ypres, (Dutch: leper), Belgium, a historic city in West Flanders province, near the French border. During the Middle Ages Ypres was a major center of the cloth trade and one of the largest and richest cities in Europe. It declined in importance after the 16th century because of political and social unrest and war. During World War I Ypres was the scene of three great battles and was almost totally destroyed. Ypres was rebuilt after the war. Restored 13th-century buildings include the Cloth Hall and the Cathedral of St. Martin.

Population: about 35,084.

I, sections "The War in 1914," subtitle The Western Front, 1914: The Race for the Sea; "The War in 1915," subtitle The Western Front: Second Battle of Ypres; "The War in 1917," subtitle The Western Front, 1917: Battle of Passchendaele, or Third Battle of Ypres; also, picture titled Ypres (in 1914 section).