The Mar Thoma Syrian Christian Community founded by St. Thomas the Apostle in 52 AD remained as an autonomous Church in the unity of the Catholic Church. They remained one body and incorporated many of the customs, practices and lifestyles of this land. With the coming of the foreign missionaries and their undue interferences in the life and liturgical practices of the people, a schism occurred in 1651. A good section of the faithful eventually became Jacobites under the Patriarch of Antioch.

Ever since the schism, attempts at reunion have been made. On September 20th, 1930 the Reunion Movement took shape under the leadership of Archbishop Mar Ivanios, and assisted by Jacob Mar Theophilos, the first bishop of Tiruvalla, it became historic. It was a triumph of ecumenism as their reunion took place as a Church accepted with its peculiar liturgy, customs and jurisdiction.

As the Reunion Movement developed speedily, Pope Pius XI established the Malankara Catholic Hierarchy for the reunited people and established the Archieparchy of Trivandrum and the Eparchy of Tiruvalla through the Apostolic Constitution, Christo Pastorum Principi dated June 11th, 1932. Listed below are the most important events of the Archdiocese in the last 90 years:

1930 August 20: Mar Ivanios, Mar Theophilos and Bethany Members leaving Perunad to join the Catholic Church, came to Vennikulam and Thirumoolapuram and prepared for the Reunion.

1933 November 6: Mar Theophilos was installed as the eparch of Thiruvalla.