Archeologists have found the oldest known human ancestors in Ethiopia, including Ardipithecus ramidus kadabba (c. 5.8–5.2 million years old) and Australopithecus anamensis (c. 4.2 million years old). Originally called Abyssinia, Ethiopia is sub-Saharan Africa's oldest state, and its Solomonic dynasty claims descent from King Menelik I, traditionally believed to have been the son of the queen of Sheba and King Solomon.
Ethiopia is located in the Horn of Africa and is bordered on the north and northeast by Eritrea, on the east by Djibouti and Somalia, on the south by Kenya, and on the west and southwest by Sudan. The country has a high central plateau that varies from 1,800 to 3,000 meters (6,000 ft.-10,000 ft.) above sea level, with some mountains reaching 4,620 meters (15,158 ft.). Elevation is generally highest just before the point of descent to the Great Rift Valley, which splits the plateau diagonally. A number of rivers cross the plateau--notably the Blue Nile flowing from Lake Tana. The plateau gradually slopes to the lowlands of the Sudan on the west and the Somali-inhabited plains to the southeast.
The climate is temperate on the plateau and hot in the lowlands. At Addis Ababa, which ranges from 2,200 to 2,600 meters (7,000 ft.-8,500 ft.), maximum temperature is 26o C (80o F) and minimum 4o C (40o F). The weather is usually sunny and dry with the short (belg) rains occurring February-April and the big (meher) rains beginning in mid-June and ending in mid-September.
Ethiopia's population is highly diverse. Most of its people speak a Semitic or Cushitic language. The Oromo, Amhara, and Tigreans make up more than three-fourths of the population, but there are more than 77 different ethnic groups with their own distinct languages within Ethiopia. Some of these have as few as 10,000 members. In general, most of the Christians live in the highlands, while Muslims and adherents of traditional African religions tend to inhabit lowland regions. English is the most widely spoken foreign language and is taught in all secondary schools. Amharic is the official language and was the language of primary school instruction but has been replaced in many areas by local languages such as Oromifa and Tigrinya.