This was the British unrequired cover plan for ‘Ironclad’ to be implemented in the event that the latter had to be postponed (April/May 1941).
In April and May the London-based Inter-Service Security Board developed and supervised the execution of the cover plan for the 'Ironclad' invasion of the Vichy French island of Madagascar. The expedition was to sail from Scotland, pause in West Africa to collect supplies, pass round the Cape of Good Hope, re-form at Durban in South Africa, and then proceed to the planned assault on Diégo Suarez on the north coast of Madagascar. The object of 'Goldleaf-Heritage' was to prevent any accurate information about the 'Ironclad' operation from reaching the Vichy French. The deception undertaking initially promulgated was based on the 'story' that the expedition was destined initially for Trincomalee in Ceylon but ultimately for Burma. In the middle of April, however, it was decided that the current disposition of British naval forces in the Indian Ocean made Trincomalee an implausible objective, so a new 'story' was developed to suggest that the expedition was destined initially for the Middle East and ultimately for an attack on the Italian-held Dodecanese islands group in the Aegean Sea.
It was appreciated that Durban was the point of greatest risk, for by the time the expedition reached that port, the various sealed orders would have been opened and the force briefed on the operation, and Axis intelligence elements were active in nearby Portuguese East Africa. The South African authorities were brought into the 'Goldleaf-Heritage' secret, and the help of Colonel Dudley W. Clarke’s North African and Middle Eastern 'A' Force deception organisation was enlisted. 'A' Force therefore sent a supply of maps of the Dodecanese islands group to the local intelligence authorities at Durban along with the necessary instructions, and embarked in Egypt on the task of spreading the 'news' that a convoy from the UK was on its way. Preparations were made to receive the ships at Suez and to encamp the troops near Ismailia for a period of rest and final training.
On 5 May the Turkish consul on Rhodes told the British that the Italian commander on Léros island had just made a speech warning that a British attack might be launched from Egypt, and that there was great activity on both Léros and Rhodes to strengthen the defences and also to mine bridges and beaches.
On that same morning the 'Ironclad' landing on Madagascar had achieved total surprise. Whether or not the Axis powers and Vichy France had connected the supposed threat to the Dodecanese islands group with the convoy at Durban, security in both the UK and Durban had clearly been satisfactory, though it had to be admitted that the general opinion in Durban had been that the expedition must be destined for Madagascar.
Analysis after the event revealed the weaknesses of what had to be admitted was a 'hazy' plan. Even if the Germans and Italians did know of the expedition, and did connect it with either the Middle East or Burma, was there any reason they should share that information with the French? Even so, the ISSB and Clarke believed that 'Goldleaf-Heritage' had been successful. Strategic, operational and tactical surprise had been achieved; the tightness of security in the UK had been confirmed; and it had been shown once again that the Germans and Italians were prepared to swallow Mediterranean 'stories' which reached them. Moreover, later in 1942 'Goldleaf-Heritage' would prove to have afforded valuable experience for the creation of deception plans to cover the 'Torch' invasion of French North-West Africa.