Hey there!
I hear a lot about Canadians, Aussies, Kiwis, and Indians always being there but never a lot about the South Africans who were apart of the Commonwealth. So what did they do? What engagements did they fight at, or were best known for?
BTW I am loving AskHistorians, it's like having direct access to the History Channel!
In WWI South Africa joined the allies. Then South Africa invaded German South-West Africa (now Namibia) by July 1915 the German forces had surrendered. After the war South Africa was given the job by the league of Nations to govern and prepare Namibia for independence. Later parts of the South African army was shipped to France to fight. As well as more then 20,000 troops fighting in German East Africa and some in Palestine. overall there were more then 231,500 South African solders in the war.
As for the second world war the South African military mainly saw action in north Africa and Italy as well as some joining the Royal Air Force. Overall there were about 334,000 men in the South African military during.
http://www.delvillewood.com/premiereguerre2.htm
In WWI the South Africans contributed a brigade of infantry to serve in Europe as well as providing troops for local action against German colonies in sub-Saharan Africa.
The South Africans formed a brigade of infantry and were involved in the Somme, particularly at Delville Wood near Longueval. This is the location of the SA War Memorial - which is worth a visit, a portion of the battle site has been preserved as it was at the armistice.
Overall casualties of the brigade were 300% of its original establishment.
In WWII, pilots were trained at the Empire Air Training Scheme in the Transvaal.
South Africa also contributed troops who fought mainly in north Africa and Italy. They frequently used the Marmon Herrington armoured car.
http://en.wikipedia.org/wiki/Marmon-Herrington_Armoured_Car
Many South Africans were captured when Tobruk fell in the battle of Gazala. Two complete brigades of the 2nd SA Infantry Division were captured more or less intact.
There was also a South African armoured division (the 6th Armoured Division) which was formed out of necessity because there were insufficient volunteers to keep two infantry divisions in the fields (even this incorporated a British Guards Brigade). This division saw little to no action in north Africa but did see extensive action in Italy.
Edited: For a better answer.