The Battle of Madagascar was an Allied campaign to capture the Vichy French−controlled island Madagascar during World War II. The seizure of the island by the British was to deny Madagascar's ports to the Imperial Japanese Navy and to prevent the loss or impairment of the Allied shipping routes to India, Australia and Southeast Asia. It began with Operation Ironclad, the seizure of the port of Diego-Suarez near the northern tip of the island, on 5 May 1942.