The Amharas, comprising about 22%, are traditionally Ethiopia's educated ruling class, providing the leadership both of the Derg and of Haile Selassie's empire.

ECONOMIST: Ethiopia

Eritrea became independent from Ethiopia in 1993, two years after Ethiopian and Eritrean rebel movements had jointly overthrown the brutal Derg regime in Addis Ababa.

BBC: NEWS | Africa | New war fears in Horn of Africa

Here you have two countries that's succeeded in building a - something close to a partnership through the overthrow of the Ethiopian junta that was called the Derg in early '90s.

NPR: Africa Update: Somalia, Eritrea and Sudan