[7] Another Thomas, a rich and influential merchant from South Mesopotamia, had trade relations in the fourth century with the Malabar coast.

The king might have welcomed the new migrants to keep better trade relations with the Middle East and to import the material and technical resources of the immigrants.

The migration, according to tradition, happened in 345 A.D.[14] Considering their distinctiveness including their culture, language, customs, food, and dress from the natives, the migrants preferred to live as a colony without having marital relations with others.

[16] Honoring the new migrants and their leader Kynai Thomas, the king offered 72 privileges for the Christians acknowledging them as higher class people in his kingdom.

[25] According to the traditional song, the Catholicos of the East had promised the migrants that he would send bishops to succeed Urha Yausef to continue the pastoral service for the Christians in Malabar.

Thus, the bishops from the Chaldean church continued to succeed one another in serving the St. Thomas Christians in Kerala until the end of the 16th century[26][27] when the missionaries from Europe took over the pastoral leadership along with the European colonization.

[25] The Southists had to leave their settlement in Kodungalloor because of the destruction of their colony during the war between the Kingdom of Cochin and Zamorin of Calicut in the 16th century.

[28] The community migrated to cities, mainly of river banks, like Udayamperoor (Diamper), Kaduthuruthy, Chungam (Thodupuzha), Kottayam, and Kallissery.

The Synod of Diamper held from 20 to 26 June 1599 paved the way for revolt of Syrian Christians of Malabar against the Portuguese Jesuit missionaries because of the forceful changes they introduced in the form of worship and governance different from what had been practiced before.

[citation needed] The revolt against the Latin bishop came to a climax on 3 January 1653 with the Coonan Cross Oath of the Syrians at Mattancherry near Kochi.

Though many compromised with the Portuguese archbishop after the revolt, the others made Archdeacon Thomas Parambil their "bishop" with the imposition of hands by 12 priests at Alangad.

[36] While establishing the Vicariate of Kottayam common for Southists and Northists, the Holy See ordered Bishop Charles Lavinge to appoint a separate vicar general for the Knanaites.

Mathew Makil started Sisters of the Visitation of the Blessed Virgin Mary (SVM) for Knanaya women at Kaipuzha on 24 June 1892.

The Knanaya Vicar General, Mathew Makil was appointed as the head of Changanacherry Vicariate that consisted of Southists and Northists ("Quae Rei Sacrae").

So, Alexander Choolaparambil took initiative to apply to the Holy See for permission to use the Antiochian Syrian Rite for those who reunite with the Catholic church.

Pope Pius XI elevated the Vicariate Apostolic of Kottayam to an eparchy on 21 December 1923 and appointed Alexander Choolaparambil as its bishop.

[52] He was pioneer in the reunion of Knanaya Jacobites to Catholic faith, getting permission from the Holy See to use the Syro-Malankara Rite, and in leading the migration to virgin land in Northern Malabar during the economically difficult time of the World War II.

Thomas Poothathil who had special concern for the poor, especially differently abled children and women, founded Sisters of St Joseph Congregation (SJC) at Kaipuzha on 3 July 1928.

[58] With the directive of Pope Pius XII, the Oriental Congregation extended the jurisdiction of the Eparchy of Kottayam also to the then extended territory of the Syro-Malabar Church by its decree 1812/48 (Quae Suddistica Gens)[59] Pope Pius XII elevated the Diocese of Changanacherry as an archdiocese and made Kottayam and Pala at its suffragan dioceses ("Regnum Caelorum") on 26 July 1956.

[67] Pope John Paul II officiated the Episcopal Consecration of Mathew Moolakkatt along with other bishops at St. Peters Basilica in Vatican City on 6 January 1999.

[68] Pope John Paul 11 made a sovereign decision on 23 December 2003, that the status quo (pro gente suddistica) of the Eparchy of Kottayam must be maintained and left it to the Bishops' Synod of the Syro-Malabar church to decide on the desired enhancement of the juridical status of the Eparchy of Kottayam.

[44] On 21 March 2005, the Congregation for the Oriental Churches issued a letter of no-objection to the decision of the Syro-Malabar Bishop's synod to elevate the Eparchy of Kottayam as an Archeparchy.

[44] At the retirement of Archbishop Kuriakose Kunnacherry, Co-adjutor Bishop Mathew Moolakkatt took over as the Metropolitan of the Archdiocese of Kottayam on 14 January 2006.

Thomas Poothathil the founder of St. Joseph's Congregation, were declared Servants of God at Christ the King Cathedral, Kottayam on 26 January 2009.

The following are the Apostolic Nuncio, missionary archbishops and bishops who have served or serving in the Latin Archdioceses and dioceses: (+ indicates the end of service and the year of death) Knanaya who have migrated from South Mesopotamia to South West India in 345 AD, kept migrating later to Northern part of Kerala, outside Kerala state in India, and other countries all over the world.

[93] The Knanites in diaspora established Knanaya associations, chaplaincy, missions, and parishes wherever possible under the Latin hierarchy and later under Syro-Malabar dioceses.

The first Knanaya Catholic church of the diaspora Knanaites was established in Chicago on 3 September 2006 under the leadership of Vicar General Fr.

[105] Europe: Pope Francis established the Syro-Malabar Eparchy of Great Britain (for England, Scotland & Wales), with its see in Preston and Joseph Srampickal as the bishop on 28 July 2016.

[107] The countries and the numbers of Knanaya Catholic families are: Italy - 650, Ireland - 160, Malta - 140, Germany - 125, Switzerland - 90, Austria - 55, and France - 30.

[102] Oceania: Pope established the Syro-Malabar Eparchy of St. Thomas, the Apostle, Melbourne, Australia on 11 January 2014 with Bosco Puthur as its first bishop and the Apostolic Visitor to New Zealand.