The Oromo were colonised during the last quarter of the nineteenth century by a black African nation - Abyssinia - with the help of the European colonial powers of the day. During the same period, of course, the Somalis, Kenyans, Sudanese and others were colonised by European powers. The fact that the Oromo were colonised by black African nation makes their case quite special.

During the process of colonisation, between 1870 and 1900, the Oromo population was reduced from ten to five millions. This period coincides with the occupation of Oromo land by the Abyssinian emperors Yohannes and Menilek. After colonisation, these emperors and their successors continued to treat Oromo with utmost cruelty. Many were killed by the colonial army and settlers, others died of famine and epidemics of various diseases or were sold off as slaves. Those who remained on the land were reduced to the status of gabbar (a peasant from whom labour and produce is exacted and is a crude form of serfdom).

Haile Selassie consolidated Yohannes and Meniiek's gains and with the use of violence, obstructed the process of natural and historical development of the Oromo society - political, economic and social. In all spheres of life, discrimination, subjugation, repression and exploitation of all forms were applied. Everything possible was done to destroy Oromo identity - culture, language, custom, tradition, name and origin. In short Haile Selassie maintained the general policy of genocide against the Oromo.