After the fall of France in June of 1940, France’s overseas colonies declared for either De Gaulle’s Free French or Germany’s puppet Vichy Regime. The large island of Madagascar off the East African coast declared for the Vichy.
The island sat astride the Mozambique Channel, through which vital shipping transited that the Allied forces in India, Egypt, and the Western Desert depended upon. Though the Vichy were technically German allies, the French on Madagascar left the British and American convoys that passed by alone. However, British codebreakers discovered that the Japanese were in negotiations with the French to use one of the many ports in Madagascar as a secret submarine base, if not seizing one outright. The largest of which was the port of Diego Suarez on the very northern tip of the island. After the Japanese raids into the Indian Ocean in April 1942, the possibility of Japanese submarines severing the Eighth Army’s lifeline through the Mozambique Channel was too likely to ignore.
Just seven weeks after its first proposal, a joint Combined Operations’ Commonwealth/British task force arrived off of Diego Suarez. Such importance was given to the operation, codenamed Ironclad, that the invasion force consisted of ships and troops urgently needed in the Mediterranean, Western Desert, or Burma. The large force sailed from Britain in late March and assembled along the way in Sierra Leone and South Africa. It consisted of the old battleship Ramilles, the carriers Indomitable and Illustrious, an almost excessive assortment of support ships, and carried three British infantry brigades and the No 5 Commando to take on the 8000 odd Vichy French defenders, mostly Senegalese and Malagasy tirailleurs.
Utilizing copious amounts of South African photo reconnaissance, the landing craft expertly navigated the coral reefs and disgorged their troops on shore about ten miles from the port in the early hours of 5 May 1942. The landings were generally unopposed, but just inland the brigades ran into tenacious and well planned French resistance which lasted all day and into the next. Despite advantages in almost every category, including airpower, the British advance was stopped cold by the French and the tirailleurs. The deadlock was only broken when the old destroyer HMS Anthony pulled alongside the Ramillies and embarked its compliment of fifty Royal Marines who until then were destined to listen to the fighting on shore in between watches on the big ship. That evening, the Anthony sailed around to the east end of the island and approached Diego Suarez from behind, past French defenses completely surprised by the audacious maneuver. Despite heavy incoming fire, the destroyer pulled up to the quay with guns blazing and the fifty Royal Marines swarmed ashore. They rushed into the port and created a “disturbance in the town out of all proportion to their numbers”. They stormed the French commandant’s house and headquarters, the naval barracks, and rounded up and captured every Frenchman they could find. When news of the naval commandant and garrison commander’s surrender reached the front lines and fighting some miles away to the west, the French resistance crumbled. However, their surrender only affected the fixed French fortifications around the port, and the French governor maintained control of most of the tirailleurs. They withdrew into the interior of the large island where they would continue resistance for another six months. The governor only surrendered after receiving news of the Vichy French capitulation in North Africa after the Operation Torch landings in November.
Operation Ironclad was the first successful large scale Allied amphibious invasion of the Second World War. After the disaster of the invasion of Norway in 1940, the Allies came a long way in amphibious operational competency, mainly through the tactics, techniques, procedures, and specialized craft and equipment employed and improved upon by Lord Mountbatten’s Combined Operations and commandos. The lessons learned during the planning, preparation, and execution of Ironclad paved the way for larger and more successful (and not so successful) operations in 1942, such as the Raid on Dieppe, the Watchtower landings on Guadalcanal, and the Torch landings in North Africa.