Saint Thaddeus, Apostle of the Seventy, was born in the Syrian city of Edessa and was of Hebrew descent. He should not be confused with Saint Jude, also known as Thaddeus or Levi, who was one of the Twelve Apostles.
After being baptized by John the Forerunner in the Jordan River in Jerusalem, Saint Thaddeus became a follower of Jesus. He was chosen by the Lord to be one of the Seventy Disciples and was sent to preach in various cities and places where Jesus intended to visit.
Following the Ascension of Jesus, Saint Thaddeus preached the Gospel in Syria and Mesopotamia. He traveled to Edessa, where he converted King Abgar, the people, and the pagan priests to Christianity through his preaching and miracles. He established priests in Edessa and built up the Church there.
Despite being offered rich gifts by King Abgar, Saint Thaddeus refused and continued to preach in other cities, converting many to the Christian faith. He founded a church in Beirut and peacefully passed away there in the year 44.
According to some sources, Saint Thaddeus was beheaded by the sword in the Artaz region in the year 50 after enduring various tortures. Eusebius identifies him as one of the Seventy Apostles rather than one of the Twelve Apostles.
St. Thaddeus encountered John the Baptist and Jesus, becoming a disciple of Christ. He was later sent by Jesus to Edessa, where he baptized King Abgar and many others, leading to the spread of Christianity in the region. He preached in Syria and Phoenicia before his death in Beirut.