A Class A mandate territory was considered advanced enough politically and economically that a provisional independence could be granted, albeit under the administration of a member state of the League of Nations1 – "subject to the rendering of administrative advice and assistance by a Mandatory until such time as they are able to stand alone2." No African colony was considered advanced enough to be designated a Class a mandate – only former Turkish provinces of Iraq, Syria, Lebanon, and Palestine were included. All Class A mandates gained full independence by 1949.
A Class B mandate territory was not considered advanced enough politically and economically that independence could be recognized at that time, and thus they were placed under the administration of a League of Nations member state.
Most of the German colony of Kamerun was mandated to France, with two small sections on the north-west border with Nigeria being administered by Britain (20 July 1922). British Cameroons was somewhat neglected, and there was a significant influx of people from Nigeria. French Cameroon was administered on the same basis as the rest of French equatorial Africa.
Most of German East Africa was mandated to Britain4 as Tanganyika (on 20 July 1922), with the small territory of Ruanda-Urundi (now Rwanda and Burundi) mandated to Belgium on 31 August 1923. Unlike neighboring Kenya, British administered Tanganyika didn't suffer an influx of European settlers – this was a significant (positive) factor when the country approached independence. In 1925 Belgium formed an administrative union between its Ruanda-Urundi mandate and the Belgian Congo. A small triangle of land to the south of German East Africa, the Kionga triangle was given over to Portugal, and added to their colony of Mozambique.
League of Nations Class C Mandate Territories
A Class C mandate territory was not considered capable of sustaining an independent state due to its sparse population, small size, remoteness, especially where the territory bordered on that of the mandatory authority. In Africa German South-West Africa (now Namibia) was given on 1 October 1922 as a Class C mandate to the Union of South Africa. (Elsewhere in the world New Guinea was mandated to Australia, Western Samoa to New Zealand, and the north-Western Pacific island to Japan.) Indigenous peoples in the territories were given the same safeguards as those in Class B mandated territories.
The mandates were theoretically supervised by the League of Nations permanent Mandates Commission, but in reality this was run by those countries which had been granted mandates. The system was replaced after World War II by UN trusteeships (in 1946).
1 In reality this meant one of the Allied countries that fought in that region.
2 Paragraph 4, Article 22 of the Covenant of the League of Nations.
3 Paragraph 6, Article 22
4Britain was at first reluctant to take the whole of Tanganyika as a mandate. According to Smith and Nöthling, North of the Limpopo: Africa since 1800 "control of the south [of Tanganyika] was … initially offered to Italy and when it refused, it was offered to the United States. Only after the Americans had also rejected the suggestion did the British, on the insistence of Smuts, agree to take over the [whole] territory as a B-mandate."