Oromos and other nations, which have been conquered, neither accepted the colonial hegemony nor assimilated with colonisers. The Oromos resisted Ethiopian colonial expansion and domination both militarily and culturally in localized and scattered ways during the second half of the 19th century and the first half of the 20th century.

To mention a few:
In 1936 Oromo leaders appealed via the British Government to League of Nations to establish a mandate over them until they achieved self-government.

In 1941-43 the Rayya Oromo revolted against the colonial regime but was silenced by the British Royal Air Force stationed in Aden. In the same year, the revolt in Ogaden (of the Ogadenia) was brutally suppressed.

From 1962 on, the Mecha-Tulama Self-help Association has attempted to promote Oromo culture and some rural development activities in Oromia inline with the then Ethiopian constitution. This association was banned in 1967 while some of its leaders were sentenced to death and others to life imprisonment.

In 1968, the brutal imperial force suppressed the Bale anti colonial resistance.