For a comprehensive understanding of this article, first read:
Apostle Thomas in India
Early Christians of India
Western Influence on Thomas Christians
Orthodox Churches in India
Because of the Latinizing policy of the Portuguese a large number of Malabar Christians became separated from the Catholic Church and joined the Jacobite Church of Antioch. They were not truly happy with it and repeatedly sought to return to the Catholic fold with self-respect. Such efforts were constantly thwarted by the Latin domination. The hostile attitude of the missionaries towards the Jacobite metropolitans who were in favor of union with the Catholics heightened the tension.
In the second half of the 18th century, the requests of Mar Dionysius I (alias Mar Thomas VI), one of the then bishops of the non-Catholic Thomas Christians for being received into the Catholic Church, were looked upon with suspicion by the Padroado and the Propaganda prelates. This made the Thomas Christian priest Kariattil Joseph (an alumnus of the Propaganda College, Rome) take steps to go to Rome. In Rome he did not get a cordial reception. While he was in Lisbon, Kariattil, his rite having been changed into Latin, was consecrated archbishop of Cranganore under the Padroado, on Dec. 16, 1782. With all faculties to receive Mar Dionysius I into the Church, Kariattil returned to Malabar. But before reaching Malabar he met with a premature death in Goa on Sept. 10, 1786. This is well described in Vathamanapusthakom, the first travelogue written in Malayalam, by Fr. Thomas Paremakal the co-traveler of Kariattil. After Kariattil’s death, Paremakal was nominated Administrator (Governador) of Cranganore.
Later, the S. Congregation was prepared to accept Mar Dionysius I as the bishop of his own people on condition that his successor was to be elected by the people and confirmed by Rome. The Vicar Apostolic began sending reports, which were not very favorable. The faculty given to the archbishop of Goa by the Pope on Aug. 27, l794, did not go beyond accepting Mar Dionysius I as a priest. This was thoroughly disappointing.
However, through the efforts of Thachil Mathoo Tharakan, Mar Dionysius I embraced the Catholic Church at an unauthorized assembly on June 21, 1799. Mar Dionysius I promised he would remit a sum of money to the Travancore government if he reverted to Jacobitism. According to the accounts kept by the Thomas Christians, Mar Dionysius I made the profession of faith according to the formula of Pope Urban VIII and also accepted the "synod" of Diamper which the missionaries were insisting upon as a condition sine qua non for reunion. Neither the Vicar Apostolic nor any one else did anything in the matter. Nobody was found to receive Mar Dionysius I legally into the Catholic Church even as a priest. After six months he returned to Jacobitism and remitted the above mentioned sum to the Travancore government. There is no justification for this sort of hostility and stubbornness of the authorities of the Catholic Church. Rome does not seem to have known of the affair in time; otherwise things would perhaps have taken another course. Mar Dionysius I, who was not satisfied with the Jacobite Church, invited the Church Missionary Society (CMS) consisting in Anglican missionaries to reform the Jacobite Church, which later paved way for the birth of another Church in Malabar, the Mar Thoma Church.
The Malankara (Orthodox) Churches in Malabar had always a sort of tension with the Jacobite Patriarchate in Antioch, and so from those Churches there had always been attempts to restore communion with the Holy See of Rome. Mar Ivanios, the founder of the "Order of the Imitation of Christ", after much study and prayer determined to be reunited with the Catholic Church. In 1926 a Jacobite Episcopal Synod at Parumala, empowered Mar Ivanios, Metropolitan of Bethany, to enter in to negotiation with Rome to effect a reunion with the Catholic Church under the express condition that the ancient and venerable tradition of the Malankara Church should be kept intact. Pope Pius XI graciously accepted the condition and welcomed the reunion. Accordingly, Archbishop Mar Ivanios and his followers made their profession of faith on 20th September, 1930 and were duly received into the Catholic Church. By the apostolic constitution, Christo Pastorum Principi, Pope Pius XI constituted the Malankara hierarchy on 11th June, 1932 with Mar Ivanios as archbishop of Trivandrum and Mar Theophilos as the sufragan bishop of Thiruvalla.Mar Ivanios took possesion of his Metropolitan See of Trivandrum on 12th March, 1933.
The Syro-Malankara Church is the third hierarchy of the Catholic Church in India. It is granted all the rights and privileges and its own liturgy and legitimate customs of the Antiochene Rite, and also administrative autonomy. The married clergy was retained but was asked to observe priestly celibacy in the future. The Church also has adopted a few laws, customs and practices of the Latin Rite.
The Syro-Malankara Church, at present, has two Archdioceses: Trivandrum, with one suffragan diocese of Marthandam, and Thiruvalla, with two suffragan dioceses of Sultan Battery and Muvattupuzha. There are 300,000 faithful with 5 bishops, 500 priests and 1200 religious men and women as members.