The most recent study on migrations in the East African region is showing that Ugandas history had been written in a simplistic way describing how the Bazungu came to east africa and especially Uganda and found Royal kingdoms of Bunyoro, Buganda and Ankole
But now there is evidence that these kingdoms were organized not by the natives but by the new conquerors who had just moved from the far north as told in this very interesting article
http://allafrica.com/stories/200706251304.html