A Muslim leader, Imam Ahmed Ibn Ibrahim
El-Gazi (Grangn), invaded most of Oromia, Abyssinia and Sidama land, which
comprised much of the territory of present day Ethiopia, and changed the
balance of power in favor of the Muslims.
A number of Abyssinian kings tried to
militarily defeat Oromo but failed because of the strength of the Oromo
cavalry and the unity of the Oromo communities.
A monk by the name Bahrey first wrote about the
so-called "Oromo Invasion of Ethiopia," a tale almost
invariably accepted by European historians as a fact.