Challenge: African Great Power

Britain loses the ARW worse so that loyalist refugees are forced to flee to South Africa rather than Canada and set up a highly efficient slave based economy. (Sorry:D)

Somewhat more seriously, as has already been mentioned a South Africa that avoids apartheid is probably the best bet. As to how to achieve it - more British immigration in the 19thC so the Afrikaners never get a majority would help, so would a slightly more enlighted native policy so that major groups like the Zulu and Xhosa preserve their independence (Swaziland or Lesotho style) under British protection so South Africa doesn't have to put so much time and effort into keeping them down. Maybe throw in some more British colonies in the region (the Rhodesias, Nyasaland) into a federal state and add in some other random bits and pieces such as St Helena and Tristan da Cunha to meet the overseas territories arrangement and you should at an absolute minimum have a country that is the most powerful in the southern hemisphere.
 
Here's an idea, Ethiopia as the African Japan. Just have Ethiopia taking the same path as Japan, ie initially isolated, then starting to open up to western merchants, taken in alliance with UK (just like Japan) builds up technology and industrial base while retaining its Emperor. Then let's cut to the early 20th century and Mussolini trying for Rome vII and gets a big can of whoop butt handed to him and reparations are...a bit of Italy for Ethiopia. (I could live with that and find it satisfying bearing in mind how nasty the Italians got in OTL Ethiopia, one could call this TL getting its deserts, justly)
 
Ethiopia is a strong possibility but you'd need a POD in the 1800's I think. Maybe have Ethiopia regain some access to the coast? Instead of being so isolated as Europe begins to colonize Africa Ethiopia then has access to European ideas and technology. And I think they'd gather a fair bit of support and good will from Europe and possibly aid especially if they play up the legend of Prestor John. A powerful Christian kingdom in Africa that promises to help convert their Muslim neighbors if only Europe can send aid will play well in Victorian England.

A more powerful and modern Ethiopia with access to the sea would probably avoid Italy's attempt at conquest but the chaos of the first and second world wars would give them ample opportunity to gobble up some islands in the Indian Ocean and Red Sea and possibly the coast of the Arabian peninsula. That's one of their historic possessions and it's close so I see that as a strong possibility. As we reach the mid-twentieth century Ethiopia would control access to Arabian oil and the trade routes through the Red Sea and Indian Ocean.
 
Somewhat more seriously, as has already been mentioned a South Africa that avoids apartheid is probably the best bet. As to how to achieve it - more British immigration in the 19thC so the Afrikaners never get a majority would help, so would a slightly more enlighted native policy so that major groups like the Zulu and Xhosa preserve their independence (Swaziland or Lesotho style) under British protection so South Africa doesn't have to put so much time and effort into keeping them down. Maybe throw in some more British colonies in the region (the Rhodesias, Nyasaland) into a federal state and add in some other random bits and pieces such as St Helena and Tristan da Cunha to meet the overseas territories arrangement and you should at an absolute minimum have a country that is the most powerful in the southern hemisphere.

British policy towards blacks in Southern Africa was hardly enlightened.

Many apartheid laws and customs can be drawn to British policies, such as the pass laws for example.

And Southern Rhodesia, which had a small Afrikaner population was hardly enlightened when it came to black rights. The same could be said of Natal in SA, which is the most 'English' region of South Africa - the policies there were as backwards as those in the Afrikaner-dominated Orange Free State and Transvaal.

The Cape was the most liberal and it was also Afrikaner-majority, although it had a big English population and was much influenced by English liberalism.
 
An Ethiopia that liberates its Coptic coreligionists in Egypt and forms a kingdom controlling the entire Red Sea coast of Africa. Probably would be a 'wag the dog' situation, similar to the Nubian dynasty of Egypt back in ancient times; a larger Coptic Egypt, that happens to have an Ethiopian dynasty on its throne.

Another option is to have Mali discover the New World, rather than Spain. Give them enough of a head start, and you could see them with a sizable colonial empire.
 
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