In the archdiocese, the population was 4,650,000 at end of 2004. (The population of the whole country is 1 billion). Most residents are Hindus, followed by Muslims. Syro-Malabar Catholics constitute only 10.84 per cent.
Malayalam and English are used.
The Syro-Malabar Church was known as the Church of the St. Thomas Christians until the 18th century as it was founded by St Thomas, one of the apostles of Jesus Christ. St. Thomas came to India in 52 A.D. He died as a martyr in a place called Mylapore near the present town of Chennai (Madras). His tomb is still venerated there.
As a Church that existed outside the Roman Empire, the Church of the St. Thomas Christians had little contact with the Roman or the other Churches within the empire. At the same time it maintained communion with the Church of Rome through the Church in the Persian Empire, which later came to be known as the East Syrian or Chaldean or Babylonian Church. It is believed that Christianity in the Persian Empire was introduced by the disciples of St. Thomas. It seems that the Christians in India had contact with these Christians of the Persian Empire from very early times. Given the commercial relations of India in those days, such a contact was possible.
In the middle of the 4th century or later, a group of Christians from these communities under the leadership of a merchant called Thomas of Kinayi migrated to the southern part of India known as Kerala today. The descendants of this latter group are called Knananites or Southists, and the former Northists Both of them now belong to the Syro-Malabar Church. Even now they live as two separate communities with their own dioceses and parishes.
For some unknown reasons, at least from the 8th century until the end of the 16th century, the bishops of the Syro-Malabar Church were sent from the East Syrian Church, appointed by the Patriarch of the East Syrian Church. There is a tradition which says that there were Indian bishops in the beginning, but there is little proof.
Because of the Portuguese colonization of parts of India in the early 16th century and consequent ecclesiastical arrangements, from 1600 onward, European bishops from the Latin-rite Church
The Communist Party of India (Marxist )-led political front heads the government in Kerala state while Congress is led by the opposition and the BJP (Bharatiya Janata Party), the right-wing Hindu party which has a sizeable presence in the archdiocese.
The archdiocese has road, rail and air links. Cochin International Airport is only 30 kilometers north of the Archbishop's house.
In a land area of 1,500 square kilometers, the archdiocesan territory covers the entire civil district of Ernakulam and portions of Trichur, Kottayam and Alappuzha in Kerala state, with 94,807 Catholic families.
Ernakulam is the business hub of Kerala. IT, fertilizer and tyre industries as well as several other medium-size industries are housed in the diocese.
There are well developed telecommunication networks in the archdiocese. Four television channels broadcast from Ernakulam
The literacy rate in the territory is almost 100 percent.