On the introduction and expansion of religion in Africa was not yet clear known its period by such scholars. Yet, for these events were recorded and handled by such religious institutions like the Churches, Monasteries and mosques. So, the introduction and expansion of Christianity and monasticism to northern part of Ethiopia was determined on the tradition of Ethiopian Church than any other recorded material during the ancient period of Ethiopian history (Before 1270). Due to this, Christianity was introduced to Ethiopia to Axum in the first Century A.D (particularly in 34A.D). After its introduction in the fourth century (after the declaration of Christianity as the Official state Religion) Christianity were gradually expanded to the most part of the Northern Ethiopia. Later, after the advent of the second group of Saints or monk (the Nine Saint) to Ethiopia, Christianity was expanded even if to the south, central and southwestern part of Ethiopia. Similarly, monasticism was begun in the northern part of Ethiopia in third and fourth century A.D. Before the advent of the Nine Saint to Ethiopia, there were such monks and hermits were live in Ethiopia as the monks and Hermits which served as to preach Christianity and to collect such followers on the area. These groups were called Tsadkanes (Righteous Men). As a result, there are still surviving historical heritage remaining’s like churches and monasteries in northern part of Ethiopia, which support this idea.

Keywords: Christianity, Expansion, Introduction, Monasticism, and Tsadkanes