Tewahedo (Ge'ez: ተዋሕዶ täwaḥədo) is a Ge'ez word meaning "being made one" or "unified". This word refers to the Oriental Orthodox belief in the one single unified nature of Christ; i.e., a belief that a complete, natural union of the Divine and Human Natures into One is self-evident in order to accomplish the divine salvation of humankind. This is in contrast to the "two Natures of Christ" belief (unmixed, but unseparated Divine and Human Natures, called the hypostatic union) which is held by the Catholic Church and the Eastern Orthodox Church. According to the Catholic Encyclopedia article on the Henotikon, around 500 bishops within the Patriarchates of Alexandria, Antioch and Jerusalem refused to accept the "two natures" doctrine decreed by the Council of Chalcedon in 451, thus separating themselves from the main body of the Christian Church at the time, which would later itself split in two factions (Eastern Orthodox and Catholic) in the East–West Schism of 1054, although this later event was not about Christological views.
Oriental Orthodoxy consists of the Coptic Orthodox Church of Alexandria, Armenian Apostolic Church, Syriac Orthodox Church, Malankara Orthodox Syrian Church, Ethiopian Orthodox Tewahedo Church and Eritrean Orthodox Tewahedo Church. It is known as "non-Chalcedonian", and, sometimes by outsiders as "monophysite" (meaning "One Single Nature", in allusion to Jesus Christ). However, these Churches themselves describe their Christology as miaphysite (meaning "one united nature" in reference to Jesus, the Greek equivalent of "Tewahedo").