'Stream' was a British landing at Majunga on the north-west coast of the Vichy French island of Madagascar (10/11 September 1942).
It had become clear in the aftermath of the 'Ironclad' amphibious operation against Diégo Suarez in the extreme north of Madagascar that the Vichy French administration would not yield the island willingly to the British and commonwealth forces, and there thus remained the possibility of an intensification of the Japanese submarine offensive in the Mozambique Channel. Through this strategically important passage moved most of the convoys carrying British reinforcements and matériel to North Africa, the Middle East and India, and during June and July 1942 Japanese submarines had indeed operated in these waters, sinking 20 ships (94,000 tons) before withdrawing during the later part of July.
After 'Ironclad', hostilities between the British and Vichy French on Madagascar continued at a low level for several months. After 19 May, two brigades of the 5th Division were transferred to India. On 8 June, the 22nd (East Africa) Brigade Group arrived on Madagascar, followed by the South African 7th Motorised Brigade on 24 June, and the 27th (North Rhodesia) Brigade (including forces from East Africa) on 8 August.
It was essential that Madagascar (and especially its western coast ports of Majunga, Morondava and Tuléar) be brought into the Allied fold in an enlargement of the undertaking started by 'Ironclad'. To this end the British undertook the 'Stream Line Jane' series of landings round the island with forces that would then advance inland.
'Stream Line Jane' comprised three separate sub-operations codenamed 'Stream', 'Line' and 'Jane'. 'Stream' and 'Jane' were the amphibious landings at Majunga on 10 September and Tamatave on 18 September, while 'Line' was the advance from Majunga to the French capital, Tannanarive, which fell on 23 September.
'Stream' secured Majunga, a port of the north-western coast of the island, when Brigadier F. W. Festing’s 29th Independent Brigade Group was landed there on 10 September with the support of Rear Admiral W. G. Tennant’s Force 'A' provided by Admiral Sir James Somerville’s Eastern Fleet and comprising the light cruisers Birmingham, Gambia and Free Dutch Jacob van Heemskerck, and the destroyers Napier, Nepal, Nizam, Australian Norman, and Free Dutch Tjerk Hiddes and Van Galen of the 7th Destroyer Flotilla. Air cover for 'Stream' was provided by the fleet carrier Illustrious and seaplane tender Albatross, which were escorted by the destroyers Express, Fortune, Hotspur and Inconstant.
No. 5 Commando spearheaded the landing and faced machine gun fire but nonetheless stormed the quayside, took control of the local post office and seized the governor’s residence. Having cut communications with Tannanarive, the British planned to resume their offensive before the start of the rainy season, but progress was slow. In addition to occasional small-scale clashes with Vichy French forces, they also encountered scores of obstacles erected on the main roads by Vichy French troops. The British forces eventually captured the capital, Tananarive, without much opposition, and then the town of Ambalavao, but governor Annet, who was a firm adherent of Vichy France, managed to escaped.
After 'Stream', the 29th Independent Brigade Group was later re-embarked for the 'Jane' landing of 18 September, with the same naval supporting force, at the port of Tamatave on the island’s north-eastern coast, its place in the 'Stream' operation being taken by Brigadier W. A. Dimoline’s 22nd (East Africa) Brigade Group for an advance inland toward the capital, Tananarive, which fell on 23 September.
Heavy surf interfered with the start of the 'Line' operation. As the launch of the cruiser Birmingham was heading to shore it was fired at by French shore batteries and promptly turned around. Birmingham then fired with her main guns on the shores batteries and within three minutes the Vichy French surrendered and Tamatave was in British hands. From there the South Lancashire and the Royal Welch Fusilier battalions set out to the south to link with forces there. After they had reached Tananarive, they pressed forward to Moramanga and on 25 September joined forces with the King’s African Rifles after securing the British lines of communication around the island. At the same time the East African infantry and South African armoured cars set out to find the elusive Annet.
The last major action took place on 18 October at Andramanalina, a U-shaped valley with the meandering Mangarahara river, where the Vichy French planned to ambush the advancing British forces. The King’s African Rifles split into two columns and marched around the bend of the valley and met Vichy French troops in the rear and then ambushed them. The Vichy French took heavy losses which resulted in 800 of them surrendering. A week later the King’s African Rifles then entered Fianarantsoa but found Annet gone, this time near Ihosy, about 100 miles (160 km) to the south. The Africans moved after him without any delay, but received an envoy from Annet asking for surrender terms. An armistice was signed in Ambalavao on 6 November, and Annet surrendered two days later.
Subsidiary landings between Majunga and Tamatave, round the southern part of Madagascar, included 'Tamper' at Morondava, 'Rose' at Tuléar and 'Extend' at Fort Dauphin.
The Allies had suffered about 500 casualties in the 'Ironclad' landing at Diego-Suarez, and 30 killed and 90 wounded in the 'Stream Line Jane' operations which followed from 10 September. It had been observed that the Vichy French had held out longer against the British in Madagascar during 1942 than they had against the Germans in France in 1940.
With Madagascar in their hands, the British established military and naval installations across the island, which was critical for the rest of the war. Its deep-water ports were vital to control the passageway to India and the Iranian corridor, and this was now beyond the grasp of the Axis. The whole undertaking had been the first large-scale operation of World War II by the Allies combining sea, land, and air forces. In the makeshift Allied planning of the war’s early years, the invasion of Madagascar held a prominent strategic place.
A Free French officer, Général de Division (from 1 March 1943 Général de Corps d’Armée) Paul Legentilhomme, was appointed high commissioner for Madagascar in December 1942.