The eparchy of Mananthavady was erected by Pope Paul VI, by the Bull Quanta Gloria of 1 March 1973 bifurcating the vast diocese of Tellicherry.

Population explosion and the shortage of food during the post-war period (1945-1960) induced them to migrate to the uninhabited fertile lands of northern Kerala and to some isolated pockets of Tamil Nadu and Karnataka States.

The migrated people, being agrarian, risking their own life cleared the forests and settled themselves cultivating paddy, rubber, coconut, coffee, cashew, pepper etc...

The Catholic population is mainly concentrated in Kerala, while Karnataka and Tamil Nadu regions are considered Diaspora.

The first bishop of the newly erected diocese Mandya was George Njaralakatt, the later archbishop of Tellicherry.