The Oromo people (, pron. Laurie Bauer, 2007, The Linguistics Student's Handbook, Edinburgh) are a Cushitic ethnic group who live in the Oromia region of Ethiopia and parts of northern Kenya. They speak the Oromo language (also called Afaan Oromoo), which is part of the Cushitic branch of the Afroasiatic language family.

They are one of the largest ethnic groups in Ethiopia. According to the last Ethiopian census of 2007, the Oromo numbered 25,488,344 people or 34.5% of the Ethiopian population. Recent estimates have the Oromo comprising 41,500,000 people, or 35.8% of the total Ethiopian population estimated at 116,000,000.

The Oromo were originally nomadic, pastoralist people who later would conquer large swaths of land during their expansions. After the settlement, they would establish kingdoms in the Gibe regionsPaul Trevor William Baxter, Jan Hultin, Alessandro Triulzi. "Being and Becoming Oromo: Historical and Anthropological Enquiries'. Nordic Africa Institute (1996) pp. 123–124Described in detail in G.W.B. Huntingford, The Galla of Ethiopia; the Kingdoms of Kafa and Janjero (London: International African Institute, 1955), pp. 55ff and assimilating the natives.Shiferaw Bekele, The State in the Zamana Masafent (1786-1853), p. 25Molla Tikuye, The Rise and Fall of The Yajju Dynasty (1784–1980), p. 199 The Oromo people traditionally used the gadaa system as the primary form of governance.Harold G. Marcus A History of Ethiopia. University of California Press (1994) pp. 55 Google Books A leader is elected by the gadaa system and their term lasts eight years, with an election taking place at the end of those eight years. Although most modern Oromos are Muslims or Christians, about 3% practice Waaqeffanna, the native ancient Cushitic monotheistic religion of Oromos.

Origins and etymology Historical linguistics and comparative ethnology studies suggest that the Oromo people probably originated around the lakes Lake Chew Bahir and Lake Chamo. They are a Cushitic people and prior to their expansions, they inhabited only the region of what is now modern-day north Kenya and southern Ethiopia. The aftermath of the sixteenth century Ethiopian–Adal war led Oromos to move to the north. While Oromo people have lived in the region for a long time, the ethnic mixture of peoples who have lived here is unclear. The Oromos increased their numbers through assimilation (Meedhicca, Mogasa and Gudifacha), as well as the inclusion of mixed peoples (Gabbaro). The native names of the territories were replaced by the name of the Oromo clans who settled on it while the indigenous people were assimilated.

According to Herbert S. Lewis, both the Oromo and the Somali people originated in southern Ethiopia but the Somali expanded to the east and north much earlier than the Oromo, and the Oromo lived only in southern Ethiopia and northern Kenya until the Oromo expansion began about 1530. Historical evidence suggests that the Oromo people were already established in the southern highlands in or before the 15th century and that at least some Oromo people were interacting with other Ethiopian ethnic groups. According to Alessandro Triulzi, the interactions and encounters between Oromos and Nilo-Saharan groups likely began very early.

Subsequent colonial-era travellers, geographers and official documents mention and refer to the Oromo people as Galla, which has now developed derogatory connotations, but these documents were generally written by members of other ethnic groups.Ernesta Cerulli (1956), Peoples of South-west Ethiopia and its Borderland, International African Institute, Routledge, , Chapter: History & Traditions of Origin The term Galla was in use for Oromo people by the Abyssinians, Arabs and Somalis.Juxon Barton (September 1924), The Origins of the Galla and Somali Tribes, The Journal of the East Africa Natural History Society, No. 19, pages 6–7 The original meaning of the term is heavily disputed. An outdated but popular theory among European historians during the 19th century regarding the origin of the term was the belief that it derives from the Hebrew (חלב) and Greek (Gála), milk, due to the outdated belief that the Oromos were lost white men. This name theory was especially popular among German historians who once believed that the Oromo were related to the ancient Gallic tribe in France. Another outdated theory of its origin comes from the belief that the Oromos rejected the offer to convert to Islam by Muhammad as their official religion, thus the prophet giving them the name Qal la or هو قال لا meaning "he said no".Mekonnen, Y. K. (2013a). Ethiopia: The land, its people, history and culture. New Africa Press. Some sources claim it was a term for a river and a forest, as well as for the pastoral people established in the highlands of southern Ethiopia. This historical information, according to Mohammed Hassen, is consistent with the written and oral traditions of the Somalis. Others, such as the International African Institute, suggests that it is an Oromo word (adopted by neighbors), for there is a word, , meaning 'wandering' or 'to go home' in their language.Claude Sumner Ethiopian Philosophy: The treatise of Zärʼa Yaʻe̳quo and Wäldä Ḥe̳ywåt Addis Ababa University, (1976) pp. 149 footnotes 312, Quote: "D'Abbadie claimed that the name Galla was explained to him as derived from a war cry, and used by the Gallas of themselves at war." Canadian philosophical professor, Claude Sumner, stated that the French explorer and Ethiopian traveler, Antoine Thomson d'Abbadie, claimed that the term had derived from an Oromo war cry whilst the Oromos were fighting on battlefields. The word Oromo is derived from meaning '[The] Children of Orma', or 'Sons of Men'. According to an alternative interpretation provided by Hugh Chisholm, 'Ilm Orma' translates to "son of a stranger.""

In the Emirate of Harar, Oromo were historically known as the Argetta by the neighboring Harari people.

History

The earliest recorded mention of the Oromos comes from the Italian (Venetian) cartographer Fra Mauro, who notes a Galla River south of the Awash River, in his famous Mappomondo, or map of the world, completed in 1460. The first detailed history of the Oromo people comes from the Ethiopian monk Bahrey who wrote Zenahu la Galla, or "History of the Galla" in 1593. They are also mentioned in the records left by Abba Paulos, Joao Bermudes, Jerónimo Lobo, Galawdewos, Sarsa Dengel and others. These records suggest that the Oromo were a pastoralist people who began to move in large numbers into the central highlands of Ethiopia from their cradleland in the plains of southern Ethiopia during the 16th century. A major factor of this movement was the militarization of the Gadaa system. All aspects of Oromo life was governed by the Gadaa system, a political and ritual system based on an egalitarian ethos, age grade social organization and highly structured institutions. Under Gadaa, every eight years, the Oromo would choose by consensus nine leaders known as (the nine Borana assemblies). A leader elected by the gadaa system remains in power only for 8 years, with an election taking place at the end of those 8 years. Whenever an dies while exercising his functions, (the symbol of power) passes to his wife and she keeps the bokkuu and proclaims the laws.

This large scale expansion is referred to as the "Great Oromo Migrations". Prior to this movement, the Oromos were divided into two major confederations, the Boorana and the Barento, who lived in the west and east of the Rift Valley respectively. The Barento moved in an eastern direction, eventually settling in today's Arsi, Bale, Hararghe and Wollo regions. Whereas the Boorana trekked northwest, settling in the regions of Shewa, Illubabor and Welega.W.A. Degu, "Chapter 7 Political Development in the Pre-colonial Horn of Africa" , "The State, the Crisis of State Institutions in the Horn of Africa: The Cases of Ethiopia, Sudan and Somalia", Thela Thesis (Amsterdam, 2002), page 142 According to Richard Pankhurst, a British-born Ethiopian historian, this expansion is linked to the attempted conquest of the Ethiopian Empire by Imam Ahmad ibn Ibrahim, which created a political and military vacuum that allowed the Oromo to move relatively unhindered into both the Ethiopian Empire and the Adal Sultanate. Further, they acquired horses and their system helped coordinate Oromo cavalry warriors which enabled them to fight very effectively. Bahrey argues the success of the Oromos in battle was because all Oromo men were trained as warriors, while in Ethiopia only a small section of the population were warriors, the rest uninvolved in the defense of their country. The military discipline of the Oromos was noted in the memoirs of the self-proclaimed Patriarch of Ethiopia, João Bermudes, who observed that during the invasion of Dawaro, the Oromos "did not come on without order like barbarians, but advanced collected in bodies, like squadrons.""Oromo (s. also Galla)", in Siegbert von Uhlig, ed., Encyclopaedia Aethiopica Volume 4 (Wiesbaden: Harrassowitz Verlag, 2011), p. 303.

The early 16th and 17th century witnessed the gradual integration of the Oromo into the Ethiopian Empire. Emperor Susenyos I, who came to power with Oromo support, did much to integrate them into the political establishment of the Christian state. Having grown up among the Oromo, he was fluent in their language and admired their way of life. He employed Oromo warriors, military tactics and combat formations against his rivals for the throne. Once in power, he filled high level offices with his Oromo supporters and settled various Oromo groups throughout much of Gojjam and Begemder. Under Susenyos's successors, many Oromos would continue to rise to positions of prominence in imperial service, and for a period even change the official language of the empire from Amharic to Oromiffa during the rule of the half-Oromo emperor Iyoas I. They would establish dynasties such as the Yejju dynasty that would be de facto rulers of Ethiopian Empire from 1784 to 1853 during the Zemene Mesafint, they would particularly have control over the provinces of Begemder and Gojjam. Another Oromo dynasty that would rise in the northern Ethiopian highlands was the Islamic Warra Himano (1580–1916), which transformed Wollo into a veritable Islamic state in the heartland of Christian Ethiopia. The Warra Himano would convert many Amhara Christians to Islam during its rule, and at the zenith of its power, the Warra Himano had their hegemony accepted in the various parts of Wollo: Ambasel, Qallu, Borena, Wore-Illu and Amhara Sayint. Notable rulers such as Ras Mikael of Wollo and the uncrowned emperor of Ethiopia, Lij Iyasu (1913–1916), descend from this ruling family.