Saint Jude was a disciple of Jesus Christ. He is described in several verses in the bible as a relative of Jesus specifically a cousin of the Lord. He was the brother of James who was also an apostle of Jesus. In Greek, the name Jude is Judas but to distinguish him from Judas Iscariot who betrayed Jesus, he was referred to as Jude, Thaddeus or Lebbaeus.
After the ascension of Jesus, Saint Jude preached the Gospel in Judaea and Samaria among other places. He is also reported to have visited Beirut and Edessa for the purposes of spreading the gospel. It is during his preaching in Armenia, which was by the time under the Persians, that he died a martyr. That is approximated around the year 65 AD. Together with him was Simon, another apostle of Jesus who also suffered martyrdom with Jude.
Legend stories have it that Jude was born into a Jewish family that lived in Galilee. He grew up to become a farmer and spoke both Greek and Aramaic, as was common with most people of his era and origin.
After his death, the body of Saint Jude was brought from Beirut to Rome and was placed in a crypt in the great basilica of Saint Peters. Today, people commemorate his death on the 28th of October, the same day they celebrate to life of Simon the apostle. He is invoked by people in times of hopelessness and is in fact referred to as the patron of hopeless cases.