When the First World War broke out in August 1914, the 3rd Battle Squadron was assigned to the Grand Fleet, with "Commonwealth" conducting operations around Scotland and the North Sea as part of the Northern Patrol. The 3rd Battle Squadron was also involved in patrols of the entire Grand Fleet, though it did not see action against German forces. In 1916, the squadron was detached to the Nore Command. In 1917, the "Commonwealth" was updated, the only ship of her class to receive technology equivalent to that of the dreadnoughts. She ended the war as a gunnery training ship, continuing in this role until February 1921, at which time she was decommissioned and disposed of.