There are no authentic documents to prove the establishment of this Pilgrim Centre. However evidences are there to prove that this church has existed during the period when Sakthan Thampuran (1775-1790) reigned over the erstwhile Cochin Province. It is believed that the church which is an epitome of an ancient era, dating back to the 14th Century, was established on September 8, 1381.
The church has many popular beliefs woven around it. Six centuries back Kerala was divided into numerous provinces ruled by kings and landlords. Two of such neighbouring landlords were Koratty Kaimal and Kodassery Kartha. The descendents of these two feudal lords live in Koratty even now, and this adds on to the authenticity of this belief about the origin of the Koratty Church