In the process, the local liturgical rite was Latinized, holy books were burned under the suspicion of Nestorianism, and connection with the Church of the East in Mesopotamia was denounced at the Synod of Diamper (1599).

[12][13] Coercive actions of the Portuguese padroado system ultimately caused resistance, and in 1653 a traditionalist faction of the local Christian community decided to follow Archdeacon Mar Thoma I in a rebellion, which became known as the Coonan Cross Oath.

Although they were unable to sway the Archdeacon, Carmelites gained the support of other local leaders, including Palliveettil Chandy, Alexandar Kadavil and the Vicar of Muttam, the three councilors of Mar Thoma i.

That process was initiated in 1665, when Mar Gregorios Abdal Jaleel, a bishop sent by the Syriac Orthodox Patriarch of Antioch, arrived in India.

[17][18] Though most of the Saint Thomas Christians gradually relented in their strong opposition to the Catholic influence, the arrival of the Mar Gregorios marked the new step towards permanent schism.

[24] In order to place Christians of the East Syriac Rite in India under his authority, Chaldean Catholic Patriarch Joseph Audo sent a request to Pope Pius IX, asking for confirmation of his jurisdiction.

Although the churches were called by the name Syro-Malabar (also known as Chaldean Syrians at that time), the actual situation was that from Irinjalakuda to northwards and south of Bharathapuzha River, and in some churches in Meenachil taluk, the Syro-Malabarians (also known as Chaldean Syrians at that time) were half Catholic and half Nestorian, with an East Syriac liturgy.

[25] After 1882, the majority of Mellus' followers returned to the Syro-Malabar Catholic Church, but some 8,000 Christians maintained their demand for restoration of traditional ecclesiastical order.

In order to answer those requests, Mar Abdisho Thondanat revived his activity, fulfilling the aspirations of local Christians of the East Syriac Rite for the full reestablishment of traditional ecclesiastical structure.

[26] Mar Abimalek Thomotheus organized ecclesiastical order and revived East Syriac rites and teachings in the local Thrissur church.

Thoma Darmo did not submit to the suspension, and the community became divided, splitting in two fractions, with one following the Metropolitan, and other remaining loyal to the Patriarch.

In the same time, the other part of community, that remained within the Assyrian Church of the East, were led by their own administrators and hierarchs, appointed by Patriarch Shimun XXI.

In 1995, under new Patriarch Dinkha IV of the Assyrian Church of the East, an agreement with Metropolitan Aprem Mooken was reached, thus initiating the process of reconciliation.