Oriental Orthodoxy is the faith of those Eastern Christian Churches that recognize only three ecumenical councils — the First Council of Nicaea, the First Council of Constantinople and the First Council of Ephesus. They rejected the dogmatic definitions of the Council of Chalcedon (451). Hence, these Oriental Orthodox Churches are also called Old Oriental Churches, Miaphysite Churches, or the Non-Chalcedonian Churches, known to Western Christianity and much of Eastern Orthodoxy as Monophysite Churches. These churches are generally not in communion with any of the multifarious Eastern Orthodox Churches but they are in dialogue for a return to unity.

Despite the potentially confusing nomenclature (Oriental meaning Eastern), Oriental Orthodox churches are distinct from those that are collectively referred to as the Eastern Orthodox Church. The Oriental Orthodox communion comprises Six groups: Coptic Orthodox, Ethiopian Orthodox, Eritrean Orthodox, Syriac Orthodox,Malankara Orthodox Syrian church or Indian Orthodox Church and Armenian Apostolic churches. These churches, while being in communion with one another, are hierarchically independent.

Dr Gabriel Mar Gregorios (born 26 February 1949) is Metropolitan of the Diocese of Thiruvananthapuram of the Indian (Malankara) Orthodox Church .

Mar Gregorios was born Kanjickal John Gabriel, the third son of Chacko John (Kanjickal, Thumpamon) and Aleyamma (Mulamoottil, Kudassanad). His early education was at St. Stephen's High School, in Pathanapuram . He studied English literature at Baselios College, Kottayam before completing his theological studies at the M.D. Seminary in Kottayam and at Serampore University. Later he received a master's degree in New Testament Studies from the Institut Catholique de Paris. He did research work on the epistles of Saint Paul at the Lutheran School of Theology at Chicago and post-doctoral research at Cambridge University.

Gabriel was ordained deacon on November 4, 1969 and as priest on February 8, 1974. He was vicar of various parishes in Bombay, Delhi, Kottayam, and Trivandrum dioceses for over thirty years. He was Registrar and Director of F.F.R.R.D. and competently represented the Indian Orthodox Church at ecumenical organizations such as the Orthodox-Marthoma Dialogue Forum, the Orthodox-Lutheran Dialogue Forum, the Bible Society Kerala Auxiliary Committee, and the Theological Literature Forum. He is a Fellow of the George Bell Institute, England and a professor of New Testament at the Orthodox Theological Seminary in Kottayam since 1982. In addition he is an Administrative Committee Member of Serampore University. He has authored many theological books, including Towards a New Humanity, Towards the Grace of God, and Cross and Grace.