Koonan Kurishu is a much-storied granite cross and a witness to the historic occasion during the seventeenth century when the split in the Christian community of Kerala became public and irrevocable. The story of the cross relates to the avowal of the followers of St.Thomas against the Portuguese Church, according to local historian K J Sohan. The cross is located in a small, semi-covered roadside shrine, locally called ‘Kuriachen’s Palli’, on Bazar Road in Mattancherry. In the local language Malayalam koonu is the word for ’bend’ or ‘hunch’, and kurishu is the word for cross. People say that the cross at the church has a hunch like bend and that could be the reason why it is called Koonan Kurishu.
It is believed that in 52 CE, St.Thomas, a disciple of Jesus Christ, landed in Muziris to preach Christianity and established the first community of Christians in India. Followers of St.Thomas in Kerala are called St.Thomas Christians. Through the following centuries, they remained in communion with the Church of Antioch and used Syriac as their church language. By the beginning of the sixteenth century, with the emergence of the Portuguese political power in Kochi, Jesuit missionaries started arriving in Kochi and preaching Catholicism. Jesuit missionaries tried to latinise the church in Kerala. In 1599 they organised Synod of Diamper, a council that laid down rules and regulations for St.Thomas Christians. The Synod was a bid to formally unite the St.Thomas Christians under the Roman Catholic church and bring them under the authority of the Latin Rite.
There is some historical evidence to show that although the Christian groups were brought under the same ambit, incidents of friction continued between the groups. This friction escalated till an incident in 1653 marked the split of the St.Thomas Christians from the prior union. In 1653, Bishop Mar Ahatallah of the Church of Antioch arrived off the coast of Kochi, but the Portuguese kept him from disembarking at the port. Meanwhile, rumours began circulating to the effect that the Bishop had been drowned at sea by the Portuguese. To register their protest against this incident, the St.Thomas Christians assembled at the chapel of Our Lady of Life Church at Mattancherry under the leadership of Archdeacon Thomas to swear what would be known as Coonan Cross oath. The oath was read aloud in front of a granite cross with lighted candles. It is believed that a fairly large number of St Thomas Christians gathered there and while taking the oath they held a rope that was tied to the cross. The following is an approximation of the oath that was taken on that day: ‘ By the father, the son and the holy spirit, henceforth we would no longer obey Archbishop of Goa or any other priests from St.Paul’s seminary, Goa nor would admit them.’ Historical records indicate that this oath was taken on the 3rd of January in 1653, and that this has been referred to as the Incident of the Coonan Cross Oath.
Some historians interpret Coonan Cross Oath as the first protest of locals against European colonialism. Presently the chapel in which Coonan Cross is located is a place of worship for hundreds of people on Fridays. The inner room has a distinctive mural of Christ in resurrection, and many people offer prayers here, sitting on the floor. Many people pray in this chapel to get back valuable things that have been lost. The central ritual in the church relates to the pouring of coconut oil, onto the head of the cross, which sits as a mast of a traditional Indian temple lamp.