In 1991, the Eritrean People’s Liberation Front (EPLF) and the Tigray People’s Liberation Front (TPLF) opened a new chapter in the history of the Horn of Africa, one marked by a high level of optimism with regard to prospect of democratisation in Eritrea and Ethiopia and that of sustainable peace and stability in the Horn of Africa. This was after both liberation fronts ousted from power the former military regime of Ethiopia, the Derg. Recently the TPLF has just been ousted from power in circumstances that bear a remarkable resemblance to the manner in which the Derg regime was defeated thirty years ago. Unfortunately, armed conflict remains to be the most dominant form of resolving political differences between and among major political forces of Eritrea and Ethiopia. Therefore, the prospect of sustainable peace and security in the Horn of Africa seems to have been reversed to a situation that is similar to that of pre-1991, in a much more complicated manner. This observation is true at least in terms of the devastating effects of the conflict in Tigray and the setback towards democratisation in both countries. Taking this observation as a very important vantage point of an inquisitive scholarly exercise, we discuss critical challenges of democratisation in Eritrea and Ethiopia, examined through the lens of historicity. The discussion will be enriched by identifying the most critical challenges to peace and security in the greater Horn of Africa, and by proposing practical solutions for improvement.