The Oriental Orthodox Churches are a group of Christian denominations that share a common belief in the teachings of the early Church but differ from other branches of Christianity, such as the Eastern Orthodox and Roman Catholic Churches. They include the Coptic Orthodox Church, the Armenian Apostolic Church, and the Ethiopian Orthodox Tewahedo Church, among others. These churches emphasize the importance of tradition and the teachings of the early Church Fathers. One key belief of the Oriental Orthodox Churches is their understanding of the nature of Christ, which led to the Council of Chalcedon in 451 AD. They reject the Chalcedonian definition, believing in a single divine nature of Christ, as opposed to two natures (divine and human). This