Jude was the brother of St. James and son of St. Joseph, betrothed to the Theotokos. Sometimes he is called Levi or Thaddeus (some English translations call him "Judas"). He protested along with Simon and Hosea when the elderly Joseph wanted to leave a portion of his estate to Jesus upon his death. He was often called 'brother of James' out of humility and shame for he did not believe in Christ at first, yet St. James did.
He was one of the Twelve Apostles (not to be confused with the Thaddeus of the Seventy Apostles) and after the Ascension he preached the Gospel Judea, Samaria, Galilee, Idumea, Syria, Arabia, Mesopotamia and Armenia.
In Armenia St. Thaddeus converted many followers, including Princess Sandukht, the daughter of King Sanatruk of Shavarshan, in the province of Artaz. By the order of King Sanatruk St. Thaddeus, along with his converts, were martyred in 66 A.D., for preaching Christianity