The area is in the Ethiopia Highlands and includes part of the Great Rift Valley that disects the plateaus southwest to northeast.
The northwest part is partly bounded in the north by the Blue Nile or Abay River. Numerous peaks exceed 3,500 meters.
The southeast part includes several peaks exceeding 4,000 meters; the highest is Batu. The land falls off toward the southeast, disssected by the the upwaters of the Shebel and Juba river system.
In between is the rift valley, marked by a chain of lakes--some of which are just outside this region(4). The northeasternmost lake is the source of the Awash River, which flows northeast out of the area.
Probably about nine in ten speak Oromo(5)--almost everyone beyond the capital and a few other small areas. Near to one in ten--mostly in the capital--speak Amharic. all the Oromo are Sunni Moslems; all the Amharic are Eithiopian Orthodox Christians.
The national capital, Addis Abeba, is the only city with more than a million residents.The Oromo have long been in the northeast of the area, in and south of Harer. They conquered southwestward and westward in the 16th and 17th century, enslaving and assimulating the previous inhabitants, who probably spoke Omotic and Highland East Cushitic languages.
Oromo is a Lowland East Cushitic language. Both branches of Eastern Cushitic probably came from further north, where Cushitic languages were spoken 2,000 years ago.
The ancestor of Amharic is Ethiopic, a Semitic language. This language lineage spread with the Christian(6) empire, and its assimulated slaves.
I dod not know when the Oromo converted to Islam, but it may have been quite early in the religion's history.
north, from the west
north, from the east-center
north, from the northeast, and east
south
west, from the east, and south, from the west
west, from the west
(1) More strictly transliterated from Amharic as Ityopia.
(2) Also spelled Adis Abeba or Adis Ababa.
(3) Also spelled Harar.
(4) The eastern shores of Lakes (Bahir) Ch'ew, Abaya and Awassa mark part of the border with the Southern Kilil; Lake Chamo is beyond; the five northern lakes are within.
(5) Galla is the Amharic word for Oromo, and was formerly also the label used by Christo-centric cultures.
(6) The emperor converted in the 4th century.