Just like South Africa, Zimbabwe didn't always have Caucasians there. Under Ian Smith, the blacks there were the underdogs and still are under Mugabee. He is tyrannical and deserves to be ousted.
You really have to consider all the things the British did, apparently with little conscience. Such as their occupation of India. And also during slavery and in the caribbean. Not to mention more recently in the 1970's with the depopulation of the tiny island of Diego Garcia, where the inhabitants were evicted from there by the British, so the island could be sold to the Americans, to be used as an airbase. I think the Americans paid Britain something like $1.
Because the English are a driving force within the world, (well they were before they became the 51st state) it's natural that such a nation would prevail and be strong, which is commedable, as Britain is a pretty small island, compared to many other places.