In mass rebellion against the Portuguese clergy and in particular Archbishop Francisco Garcia Mendes, the St. Thomas Christians met on 3 January 1653 at Our Lady of Mattenchery Church to convoke the Coonan Cross Oath. The oath expressed that the community would no longer obey Archbishop Garcia nor the Portuguese Jesuits but instead only recognize their native archdeacon as the governor of their church. After the oath, scholar Stephen Neill notes that the Knanaya priest Anjilimoottil Itty Thommen Kathanar of Kallissery played a major role in the eventual schism of the St. Thomas Christians from the Roman Catholic Church. Being a skilled Syriac writer, it is believed that Itty Thommen forged two letters supposedly from Mor Ahatallah one of which stated that in the absence of a bishop, twelve priests could lay hands on Archdeacon Thomas and consecrate him as their new patriarch, an old oriental Christian tradition. The two forged letters were read to mass crowds during church services and were received with much praise from the community. One of the letters was laid on the head of Archdeacon Thomas and twelve priests consecrated him as the first native bishop of Kerala. News of the event was spread throughout the churches of the St. Thomas Christians who accepted it with much joy in the fact that for the first time in their history a native bishop was consecrated.