Following the British attack on the French fleet at Mers-el-Kebir a pro-Vichy government had been installed on the island, and the British concern about the island being occupied by the Axis grew. As a result, on 5 May 1942, an amphibious force consisting of three infantry brigade-groups with naval and air support undertook Operation Ironclad. For this operation, No. 5 Commando, numbering some 365 men under the command of Lieutenant Colonel W. Sanguinetti, was attached to the 29th Brigade and landing ahead of the main force near Courrier and Ambarata Bays on the northern tip of the island and roughly to the west of Diego Suarez, they carried out a raid on a French coastal artillery battery.