(from the http://www.bibleinfo.com/en/questions/who-were-twelve-disciples webpage)
John Boanerges, son of Zebedee and Salome, brother of James, the Apostle. he was known as the Beloved Disciple. A fisherman who lived in Bethsaida, Capernaum and Jerusalem, he was a member of the Inner Circle. He wrote the Gospel of John, I John, II John, III John and Revelation. He preached among the churches of Asia Minor. Banished to the isle of Patmos, he was later freed and died a natural death. John was one of the prominent Apostles. He is mentioned in many places in the New Testament. He was a man of action; he was very ambitious; and a man with an explosive temper and an intolerant heart. His second name was Boanerges, which means son of Thunder. He and his brother, James, came from a more well-to-do family than the rest of the Apostles. Since his father had hired servants in his fishing business (Mark 1:20) he may have felt himself above the rest. He was close to Peter. They were acting together in the ministry. Peter, however, was always the spokesman for the band.
John mellowed with time. At the latter part of his life, he had forgotten everything, including his ambition and explosive temper, except his Lord's command of love.
It is said that an attempt was made on his life by giving him a chalice of poison from which God spared him. He died of natural causes. A chalice with a snake in it is his symbol.