He travelled to the missions of Madurai, in Southern India, present-day Tamil Nadu, in 1673 and preached the Christian religion in the region of the Maravar country.

The Madurai Mission was a bold attempt to establish an Indian Catholic Church that was relatively free of European cultural domination.

As such, Britto learned the native languages, went about dressed in yellow cotton, and lived like a Tamil Thuravi/Sannyasi, abstaining from every kind of animal food and from wine.

Britto tried to teach the Catholic faith in categories and concepts that would make sense to the people he taught.

Britto remained a strict vegan until the end of his life, rejecting meat, fish, eggs and alcohol, and living only on legumes, fruits and herbs.

[1][2] De Britto's preaching led to the conversion of Thadiyathevan (தடியத் தேவன்), a Maravar prince who had several wives and was required as a Christian to dismiss all but one of them.

This seashore sightseeing location is one of the most venerable pilgrim centres of Christians in the world over, as it is said to be the site of Britto's martyrdom.

There is a shrine constructed in Portuguese style containing a statue of Britto, known locally as Arul Anandar, who had modestly offered his neck to the executioner.

Thus, together with Christians, Hindus and Muslims also come to worship at the shrine in thousands, to mark respect to a unique holy man who shed his life and blood at that spot.

The strong faith and enviable ability to combine pleasure and righteousness on a pilgrimage gives a divine atmosphere to the Orur festival.

In October, nearly 25,000 pilgrims arrive from the neighbouring Sivagangai district and in December, visitors are from Madurai and Melur.

The Basilica of St. John de Britto is in the village of Orur (also spelled Oreiour), where he is a significant figure revered by the Kallar, Maravar and Agamudayar.

There is also a Church dedicated John de Britto in Sesurajapuram, Krishnagiri district of Tamil Nadu.

In Mauritius there is a chapel named St Jean de Britto dedicated to Tamil Catholics living in the area.