Raid in December 1941 were rebuffed in favour of the Commandos. The temporary attachment of the 8th Argylls over the winter of 1940-1 enabled the RM Division to develop new techniques in landing heavy weapons and training regular army troops in amphibious operations, and this was extended under Major-General Sturges by the attachment of the 29th Independent Infantry Brigade in May 1941. This expanded Division was originally assembled to provide a force to invade the Canary Isles, should Spain enter the war on the side of the Axis powers, and was then held on standby by General Harold Alexander for a range of potential amphibious operations. The last of these was Operation Ironclad, with Major-General Sturges taking part of the RM Division HQ to head up Force 121 for the amphibious assault on Diego-Suarez to deny that harbour to the new Japanese threat. However, despite supporting representations from Admiral Mountbatten who was then Chief of Combined Operations, the War Office considered the light infantry units of the Royal Marine Division to be unsuitable for the task. The Admiralty refused to approve the RM Division being brought up to a standard establishment, and so their place was taken by two brigades of 5th Division. The two Brigade Groups of the RM Division were offered to General Eisenhower for Operation Torch in the Autumn of 1942, but the offer was rejected with the role being taken instead by two brigades of the 78th Division that had been formed in May 1942 specifically for that purpose. Dissolution of the Royal Marine Division The RM Division was disbanded in August 1943 in order to provide specialist troops for the Normandy landings: RM Division HQ became Special Service Group HQ 101st RM Brigade HQ became 4th Special Service Brigade HQ 1st RM Battalion became No. 42 RM Commando 5th RM Battalion became No. 45 RM Commando 9th RM Battalion became No. 46 RM Commando 102nd RM Brigade became 3rd Special Service Brigade HQ 2nd RM Battalion became No. 43 RM Commando 3rd RM Battalion became No. 44 RM Commando 10th RM Battalion became No. 47 RM Commando RM Divisional Artillery RM Field Artillery Regiment became Royal Marine Armoured Support Group RM Light Anti-Aircraft Regiment became Landing Craft Flack gun crews RM Support Battalions 15th RM Machine Gun Battalion became Landing Craft Support gun crews. RM Engineer Field Company became six RM Landing Craft Obstacle Clearance