Ethiopian nationalism, also referred to as Ethiopianism or Ethiopianness, is a political principle centered on the unification of Ethiopian identity. The ideology was traced throughout ancient history, from Ethiopian Empire to the Derg rule. For more than a century, Amhara ruling elite used this ideology to pursue an assimilation policy and consolidate power. The conflict started between Abyssinia, ruled by Amhara ethnic groups, and various subjugated ethnic groups such as Oromo, Sidama, and Tigray. In 1991 Eritrea achieved independence as the Derg collapsed and the TPLF assumed power and created an ethnic-federal state. The Amhara culture dominated throughout the eras of military and monarchic rule. Both the Haile Selassie and Derg governments relocated numerous Amharas into southern Ethiopia including the present-day Oromia Region, where they served in government administration, courts, church, and even in schools, where Oromo texts were eliminated and replaced by Amharic. As a result of these steps, ethnic tensions surged against the Neftenya system where the Oromo, Somali, and Tigray peoples, each of whom had formed separatist movements such as the OLF, TPLF, ELF , and ONLF struggled to leave the Ethiopian Empire, which led to the Ethiopian Civil War. Oromo and Amhara nationalists continue to have conflicting narratives over the status of Addis Ababa. The Abyssinian elites perceived the Oromo identity and languages as hindrances to Ethiopian national identity expansion. Until 1991, the Amhara dominated politics in Ethiopia.