It was at the house of Saint Mark that the Lord met with His Apostles and celebrated the Passover, where the Lord appeared to them after His Resurrection, and where the Holy Spirit descended upon the Apostles on the Day of Pentecost. Thus, it is well known by all the Apostolic Churches as the first church in the world. Hence, the Coptic Church is one of the oldest churches in the world, spanning 20 centuries of history. By the end of the second century, Christianity was well established and very active in Egypt.
The Coptic Orthodox Church is one of the five most ancient churches in the world and is called the “See of Saint Mark.” The other four ancient sees are the Church of Jerusalem, the Church of Antioch (Antiochian Orthodox Church), the Church of Rome (Roman Catholic Church) and the Church of Athens (Greek Orthodox Church).