Illubabor was a province in the south-western part of Ethiopia, along the border with Sudan. The name Illubabor is said to come from two Oromo words, "Illu" and "Abba Bor(a)". "Illu" is a name of a clan, and "Abba Bor" was the horse name of Chali Shone, who founded the ruling family of the area when it was conquered by Shewa; hence IlluAbabor means the Illu belonging to Ababor(a). There is also a place called Illu-Abasambi named in the similar fashion.
Originally, its capital city was Gore, then around 1978 the capital was moved to Metu. With the adoption of new constitution in 1995, the territory of Illubabor was divided between the Gambela, Oromia and the Southern Nations, Nationalities, and Peoples Regions of Ethiopia.
Illubabor was, by the late 19th century, an Oromo state facing the prospect of forcibly being absorbed into the Ethiopian Empire, whose reconsolidation of authority over long-abandoned peripheral territories had been intensifying since the ascension of Menelik II, who had begun his southern campaigns while King of Shewa, to the imperial throne in 1889.
The last king of Illubabor was Fatansa Illu. When the imperial forces invaded Illubabor in 1889, the king sent messengers to Kumsa Mereda of Leqa Naqamte and Abba Jifar of Jimma to form an alliance to resist the imperial army. Although the messengers were warmly accepted by Kumsa Moroda, when they presented their message he declined the offer, saying that the provincial forces could not resist Imperial troops well armed with modern firearms. The messengers who went to Abba Jifar were unsuccessful. Both rulers had previously secured their autonomous status from Menilek.