She was then transferred to the Mediterranean Fleet in early 1919 and spent most of the rest of the year in the Adriatic Sea. In early 1920, the ship was in the Black Sea supporting the Whites against the Bolsheviks. "Cardiff" spent most of the rest of her time between the world wars overseas or in reserve. The ship played a minor role in World War II as she was initially assigned to the Northern Patrol, but became a training ship in late 1940 and continued in that role for the rest of the war. "Cardiff" was sold for scrap in early 1946 and subsequently broken up.