The Second Battle of Ypres was a battle of the First World War. It was fought for control of the town of Ypres in western Belgium. It happened in the spring of 1915. It was the first time that Germany successfully used chemical weapons on a large scale on the Western Front. It was also the first time a former Colonial power defeated a major European power in European soil. The battle was the beginning of a new danger; gas, which will cost both sides thousands of casualties the rest of the war.