
The Church of the St. Thomas Christians is an ancient Christian Church and an apostolic Church originated out of the evangelical endeavours of St. Thomas. The traditions current among the St. Thomas Christians hold that St. Thomas, one among the twelve apostles, after visiting Socotra came to Muzris (Kodungallore) in about AD 52. He preached to the Jewish colony and made converts, established Christian communities at seven places—Maliankara, Palayur, Paravur, Gokamangalam, Niranam, Chayal, and Kollam—and appointed leaders from the leading families Kalli, Kaliankal, Shankarapuri and Pakalomattam. From Kerala he proceeded to the eastern parts of South India and then to Malacca and China. Returning to India, he was martyred and buried at Mylapur (St. Thomas Mount) in AD 72.
In almost every century from the 3rd to the 16th we have testimony to the existence of the St. Thomas tomb in India. The 3rd-century Syrian writing the Acts of Apostle Judas Thomas (Acta Thoma) says that the apostle worked in India and met death on the top of a hill in the kingdom of Mazdai; a part of his bones was taken to Edessa by a Syrian merchant called Khabin. St. Ephrem (4th century) composed hymns on St. Thomas's mission in India, martyrdom, and removal of bones to Edessa. Gregory of Tours (AD 594), Marco Polo (1293), and the Portuguese from 1517 onwards attest to the tomb at Mylapur. The St. Thomas Christians were unanimous that the apostle suffered martyrdom and was buried at Mylapur.
It is the constant tradition of the Eastern Church that the Apostle Thomas evangelized India. The earliest detailed account from Syrian Christianity is the book The Acts of Judas Thomas, written in Syriac by an Edessan Syrian Christian around AD 200. The Teaching of the Apostles (AD 250) states: "India and all its countries and those bordering on it, even to the farthest Sea, received the Apostle's Hand of Priesthood from Judas Thomas." St. Ephrem and the East Syrian liturgical tradition consistently associate St. Thomas with India.
Among the Fathers and writers of the Graeco-Roman world, Gregory of Nazianzus, Ambrose, Jerome (4th century), Gregory of Tours, Isidore of Seville, and Cosmos the Alexandrine traveler hold that St. Thomas preached in India and established the Church there. The liturgical traditions of the Roman, Byzantine, and Alexandrine churches also associate the martyrdom of St. Thomas with India (Calamina/Mylapur).
The age-old consciousness of the church of St. Thomas Christians—that their origin as Christians is from the mission of St. Thomas the Apostle in India—stands sufficiently justified by the living community and its traditions, the tomb at Mylapur, the witness of the East Syrian and universal Church, and the judgment of historians.