Oromo (ōrōˈmō) [key] or Galla gălˈə, traditionally pastoral tribes who live in W and S Ethiopia and part of Kenya. They number about 20 million and are largely Muslim. Originally from N Somalia, they later migrated to the region of Lake Turkana (Lake Rudolf). In the mid-16th cent. they began to move into the Ethiopian highlands. Never a united group, they were not a serious threat to the Ethiopian state. Their raids, however, were a considerable nuisance, and they were able to establish small states in many areas nominally controlled by the Ethiopian emperor. They were used as mercenary soldiers by the Ethiopians. Oromo separatist guerrillas have campaigned against Ethiopian rule since the 1990s without any significant results. The government has responded by repressing its opponents, occasionally prompting antigovernment demonstrations. Oromo separatists have mounted occasional raids into neighboring Kenya.
See G. W. B. Huntingford, The Galla of Ethiopia (1955, repr. 1969); H. S. Lewis, A Galla Monarchy (1965).