The origins of the division of the Saint Thomas Christians into Northist and Southist groups is traced back to the arrival of the Syrian merchant Thomas of Cana (Knāi Thoma) who led a migration of Syriac Christians (Jewish-Christians) from Mesopotamia to India in the 4th or 8th century. The Knanaya claim descent from Thomas of Cana and those who came with him. The communities arrival was recorded on the "Thomas of Cana copper plates " which existed in Kerala until the 17th century after which point they were taken to Portugal by the Franciscan Order. The ethnic division between the Knanaya and other St. Thomas Christians was observed during the Portuguese colonization of India in the 16th century and was noted throughout the European colonial era.