The original rite of the Church in India was the East Syrian or Chaldean Rite. According to tradition, the Gospel was first preached in India by St. Thomas the Apostle, and it is historically certain that a Christian Church was established in Kerala at a very early date. By the 6th century, this Church was already a Syrian Church under the jurisdiction of the Patriarch of Seleucia-Ctesiphon in Mesopotamia, from whom it received its bishops. Consequently, the Chaldean Rite was universally used by all Christians in Kerala.
In the 17th century, however, the Council of Diamper (Udayamperur), convened under Portuguese influence, sought to Latinize the rite, leading to a significant division. A portion of the Church, opposed to these changes, broke away from communion with Rome and placed themselves under the Jacobite Patriarch of Antioch. This faction adopted the West Syrian Rite of Antioch, which continues to be used by the Jacobite Church to this day.
In 1930, a pivotal moment occurred when Mar Ivanios, a Jacobite Metropolitan, along with another bishop, Mar Theophilus, and a group of clergy and laity, reconciled with Rome. Upon their reunion, they retained the West Syrian Rite of Antioch, leading to the formation of the Syro-Malankara Church, which comprises Catholics who follow the rite of Antioch in communion with Rome.
Thus, within the Catholic Church in India today, two Syrian rites coexist:
Following the reform of the Syro-Malabar Rite, which removed its imposed Latinisms, both rites now serve as a living witness to the Syrian tradition of Catholic life and worship. They bear the responsibility of preserving the full inheritance of the Syrian Church within the Catholic Church, ensuring the continuation of its rich liturgical and spiritual legacy.