Bunyoro was a Kingdom within Uganda. It was dissolved during the military coup led by Milton Obote. This reflected the desire for a unitary state as opposed to a federal arrangement in which the kingdoms within Uganda would retain some degree of internal autonomy.
The Kingdom was restored in 1993.
From left to right, the rulers of Ankole, Bunyoro, Buganda, and Lango. c. 1957-1961
Source: UK National Archive Catalogue, Public domain, via Wikimedia Commons