The Cathedral Church of the eparchy of Irinjalakuda got its present existence under the nomenclature and the Canonical Status as Cathedral in the Wake of the Origin of the New Eparchy. This was effected by the amalgamation of the two independent and important parishes of the locality, namely, St. George’s Forane Church and St. Mary’s church, which amicably situated side by side for about a century. Each had its several institutions and properties as well as high resources. St. George Church is chronologically prior as it was established in 1845 A.D. This originated at the request of the Christian merchants who migrated to Irinjalakuda during the regime of Rama Varma Thampuran (known as “Sakthan Thampuran” – 1790-1805) the king of Kochi. He invited the Christian merchants from the neighboring ancient Catholic regions such as Velayanad, Mapranam, Kalparambu etc. in view of trade and industry. Thus a small Church was constructed here, then known as Kombarakunnu under the guidance of the Parish Priest of Mapranam Church. Later they tried for building a spacious Church. However, in 1874 the so called “Mellus Schism” affected the area and the majority succumbed to it. But a ministry resisted and tried to continue in the papal allegiance. With that view they constructed a new and better Church in 1880 and dedicated to the Blessed Virgin Mary (ST. Mary’s Church). Gradually several religious, educational and charitable institutions came up and flourished in the area. Though the Mellusian group got away from that influence and rejoined the Papal allegiance, both the Churches remained side by side as separate Catholic Parishes without territorial limits. They cherished Concord and Cordiality. In 1944 St. George Church was raised to the Status of a Forane Church.

But in the wake of the new eparchy with its title and headquarters in the municipal town of Irinjalakuda, the ecclesiastical authorities thought it better and convenient to amalgamate them as a Single Canonical parish to form the Cathedral of the new eparchy. Subsequently in consultation with the parish priest, Trustees and Representatives of both the parishes, Mar Joseph Kundukulam, then Bishop of Trichur could effectively amalgamate them so as to form a Cathedral Parish, newly dedicated to St. Thomas the Apostle in 1978. While St. George’s Forane Church was changed to be St. Thomas Cathedral Church, St. Mary’s Church was temporarily used as Bishop’s Chapel (Mar James Pazhayattil) and subsequently named as Spirituality Centre. Irinajalakuda is well known for its religious harmony, marketing and commercial facilities.

The Cathedral Parish has, at present a Catholic population of 14,552, belonging to 2921 families. Apart from the Eparchial office and related institutions, numerous Religious institutes, formation Houses, as well as Catechetical, educational and service centers took their origin with the benign and generous support of the Catholic Community of the area. The major religious institution to be mentioned is the Udaya Provincial House belonging to the Congregation of the Mother of Carmel. The Cathedral Parish also has its own multifarious institutes and associations thriving full swing.