The Knanaya Christians are believed to be the descendants of 72 Judeo-Christian families who migrated from Edessa (or Urfa), the first city state that embraced Christianity, to the Malabar coast in AD 345 , under the leadership of a prominent merchant Knai Thomman (in English, Thomas of Cana). They may also be related to Canaanites . They consisted of 400 people men, women and children, from various Syriac-Jewish clans. Included in the group was a Syriac Orthodox Bishop(Mor Joseph of Urfa), priests and deacons. They sailed in three ships headed by a leading ship with the flag of King David . The Syriac-Jews were granted permission to engage in trade and settle down in Kodungallur by the then ruler of Malabar, Cheraman Perumal. The event has been recorded on copper plates given to the community.
Before the arrival of the Knanaya people, the early Nasrani people in the Malabar coast included some local converts and many converted Jewish people who had settled in Kerala during the Babylonian exile and after. They came mostly from the Northern Kingdom of Israel. According to tradition, Knanaya Christians are also known as Southists (Thekkumbhagar in Malayalam) as they hailed from the southern province of Israel known in the Old Testament as the Kingdom of Judah. The rivalry between the northern kingdoms and the Kingdom of Judah since Old Testament times led to the difference among the Nasranis as Northists and Southists. This led the Knanaya people to become an endogamous people within the Nasrani community.
The Hebrew term Knanaya or K'nanaim, also known as Kanai or Qnana'im, (for singular Kanna'im or Q'nai) means "Jealous ones for God". The K'nanaim people are the biblical Jews referred to as Zealots (overly jealous and with zeal), who came from the southern province of Israel. They were deeply against the Roman rule of Israel and fought against the Romans for the sovereignty of the Jews. During their struggle the K'nanaim people become followers of the Jewish sect led by 'Yeshua Nasrani' (Jesus the Nazarene). After the crucifixion of Jesus by the Romans in 33 CE, the Knanaya intensified their struggle against the Roman rule.
In 70 CE, hundreds of Q’nanaim zealots evaded capture from the Romans and took shelter in the fortress at Masada. In 72 CE, after a two year siege, 960 knanaya zealots unwilling to give up to the romans killed themselves before the romans could capture them. This act of martyrdom is still commemorated in Israel. In 345 CE a small group of K'nanaim merchants travelled to the Jewish trade posts at Kodungallur in Kerala and settled there. Their descendants are today known in Kerala as Knanaya Nasranis.