The history of the Kingdom of Rwanda has been challenged by fundamental studies. These indicate that, contrary to the long-prevailing historiographical tradition, Rwanda's past does not consist of the dynastic history of an elect Tutsi ethnic group, but was formed from several nuclei which underwent assorted evolutions. A Tutsi royalty emerged (Nyiginya dynasty) and extended its territory from central Rwanda using a variety of methods; its powers were nevertheless limited depending on the occupied or colonized region. At the end of the 19th century, the kingdom reached its furthest territorial and political expansion. The arrival of Europeans progressively altered the face of the kingdom. It was first colonized by the Germans, then became a mandatory territory under Belgian supervision after World War I, and the system of indirect administration shook its complex but fragile sociopolitical cohesion. Revolution and subsequent independence marked the end of the Tutsi kingdom in favor of an independent Hutu republic.