According to the strong and staunch traditional belief of the Christians on the coast of Malabar, St Thomas, the Apostle of Christ landed in Kodungallur (Cranganore), the capital of the Chera Empire in the year 52 A.D. Persians, Greeks and Romans had trade with Kodungallur, which was also known as Muziris or Mahodayapuram, at present situated in the District of Trichur, as an important centre for their trade.
St. Thomas preached the Gospel and converted many to Christian faith and founded small Christian communities in Palayur, Cranganore, Parur, Kokamangalam, Niranam, Quilon and Chayal (Nilackal). According to tradition, the first place of his apostolate was Palayur, the most ancient shrine of the Archeparchy of Trichur. Palayur had a Jewish colony from pre-Christian era onwards until last few centuries. Palayur can, therefore, rightly be called "the Cradle of Christianity in India". According to the Malabar tradition, He was martyred at Chinnamala and was buried in Mylapore near Madras. in 72 AD.
According to the ancient song Ramban pattu the Apostle Thomas ordained and appointed Kepha as the head of the Indian Church at Kodungallur and Paul as Bishop of Mylapore, thus giving shape to the first Indian Christian Hierarchy.
From the 4th century onwards St. Thomas Christians established relationship with the Church of Persia. Bishops who came to India from that Church also had their residence at Kodungallur while they held the title of the "Metropolitan and Gate of all India". The traditional jurisdiction of the Metropolitan head of the Indian Church was "the whole of India". The 'Metropolitan' changed his residence from Kodungallur to Angamaly in the 16th century due to certain political reasons. The territorial jurisdiction was slowly limited. After the death of Mar Abraham in 1577 St. Thomas Christians were subjected to the Latin Bishops from 1599 and continued to be so until 1887. The See of Kodungallur, which has its origin from the time of the Apostle Thomas, was suppressed in the year 1886.