HMS Ivanhoe was an I-class destroyer built for the Royal Navy in the mid-1930s. During the Spanish Civil War of 1936–1939, the ship enforced the arms blockade imposed by Britain and France on both sides as part of the Mediterranean Fleet. Before the start of World War II, the ship was modified so that she could be used to lay mines by removing some of her armament. Ivanhoe was transferred to Western Approaches Command shortly after the war began and helped to sink one German submarine in October 1939. She was converted to a minelayer while undergoing a refit in November–December and laid minefields in German coastal waters as well as anti-submarine minefields off the British coast until she was reconverted back to her destroyer configuration in February 1940. Ivanhoe reverted to her minela