From around 200 BC to 700 AD, Axum was the seat of an Empire which extended across the Red Sea to Arabia, traded with India and China, had its own alphabet and constructed great engineering works.  In the 4th century Axum was considered to be one of the four great powers of the ancient world. The Mariam Tsion church in Axum is said to house of the Ark of the Covenant.  The ceremony at Mariam Tsion sees pilgrims from all over the country come to express thanks after the fulfillment of a wish, or in the hope of miraculous cure.