A Christian community has been existing in Kerala since the arrival of St Thomas here in AD 52. According to the local traditions and available historical documents, St Thomas ordained priests to administer the church. There was no Indian bishop at the time. The church was lead by a senior priest holding the title 'Arch Deacon'. He was the supreme authority of the Christians of the country in both spiritual and mundane affairs. Church had visiting bishops from the Persian church who fulfilled the need for an Episcopal office.
In 1599, the Portuguese almost succeeded in forcibly converting the Syrian Christians to Roman Catholicism at the Synod of Diamper. But in 1653, through the Coonan Cross Oath, the Syrian Christians broke the shackles of Rome and proclaimed their autonomy. People wished to have a local bishop as their leader and thus they elected the then Arch Deacon as their bishop. He was ordained as a bishop under the title 'Mar Thoma' by 12 senior priests (Since then, this office of the high priest is known as 'Malankara Metropolitan'. No Persian bishop was present at this ordination. It was impossible for them reach here because the Portuguese were controlling the sea-routes to India and they made it sure that no foreign bishop would reach here to help the Indian church). This bishop is popularly known as 'Mar Thoma I' in the church history and is the first Indian bishop for a Christian church. He gave brilliant leadership to the church in the midst of troubles and fought to preserve the independence of the Indian Christians. Niranam church was the head quarter of the Malankara Metropolitans.
Mar Thoma II
Before his demise in 1670, Mar Thoma I ordained his nephew as Mar Thoma II. He was a very pious man. According to a local tradition once the people of Niranam were suffering from severe drought and they appealed to Mar Thoma II for his special prayers. As a result of his prayers the village received plenty of showers. Mar Thoma II led the church for 16 years and left for his heavenly abode in 1686. His mortal remains were buried inside the Niranam Church and every year his memorial day is celebrated on 16 th April.
Mar Thoma V
In 1728, Mar Thoma V assumed the office of Malankara Metropolitan. Despite the interventions of Roman Catholics and Syrian Orthodox Patriarch of Antioch in the affairs of the Church, he succeeded in preserving the autonomy and autocephalousy of the Church. In 1751, a group of bishops and priests sent to Kerala from Syria by the Patriarch of Antioch. Their mission was to re-ordain Mar Thoma V as 'Mar Dionysius' and thereby establish the supremacy of Antiochian Church over the Indian Church. The Dutch East India Company by whose ship they traveled, put the burden of the travel expenses of the group-around twelve thousand rupees- on Mar Thoma V. But he refused to pay the amount because the foreign bishops started ordaining priests and intervene in the administration of the Church as soon as they reached here. The Dutch arrested Mar Thoma V and threatened to send him on exile. This dispute was later settled by the intervention of the Government of Travancore. The Antiochian bishops tried hard to re-ordain Mar Thoma V and bring him under the Patriarch of Antioch. But he refused to kneel down as he was strongly convinced that the Indian Church is autonomous and autocephalous in all respects and it doesn't need any external intervention in its affairs. To reinforce this, he himself ordained Mar Thoma VI as his successor in 1761 at Niranam Church without the participation of foreign bishops. During his long tenure spanned for 37 years, Mar Thoma V successfully defended the disruptive activities of Antiochian Church and Roman Catholics. He passed away on 10 th May 1765 and cremated inside the Niranam Church. Every year his memorial feast is celebrated on 10 th May on a large scale.