The Ethiopia–Somalia boundary extends 1,648 kilometers (1,024 miles) and received only a partial colonial demarcation. Both the United Kingdom and Italy had a role in shaping the modern-day border, on behalf of their colonies of British and Italian Somalilands, with the independent Empire of Ethiopia in the late 19th and early 20th centuries.

From the late 19th century to Somalia’s independence in 1960, the Somali people in eastern Africa lived under British, Italian, French, and Ethiopian rule. The United Kingdom gained control of Ethiopia’s Ogaden region during World War II. The territory was returned to Ethiopia after the war, but has not been delimited beyond a provisional line. Ogaden, or the Somali Regional State, is populated by ethnic Somalis, and the international frontier remains unmarked and practically invisible on the ground. From 1960 to today, the Ogaden region has been the primary source of deep tensions between the two States.