Nice to see you never stereotype...
The last Emperor of Ethiopia, Haile Selassie.
I would say it is true however. Following the colonial era in Africa (which incidentally was Africa's most prosperous & peaceful golden era), we have somewhere between 60-80 yrs or so of black leaders ruling in extravagant luxury & opulence in Africa, while they allow the genocide & destruction of their own country & people. Personally I can't think of a single black leader who has not raped & pillaged & plundered his own country while committing or allowing for unbelieveable atrocities, genocide & deliberate starvation of his own country.
President Mugabe perhaps is the poster child for black rulers, skimming off the foreign aid to his country, while decimating, destroying & killing his own people and destroying Zimbabwe, formerly Rhodesia which was the bread basket of Africa under white rule.