From the Treasury of Daily Prayer:

St. John was a son of Zebedee and brother of James the Elder (whose festival day is July 25). John  was among the first disciples to be called by Jesus (Matthew 4:18-22) and became known as “the disciple whom Jesus loved,” as he refers to himself in the Gospel that bears his name (e.g., John 21:20). Of the Twelve, John alone did not forsake Jesus in the hours of His suffering and death. With the faithful women, he stood at the cross, where our Lord made him the guardian of His mother. After Pentecost, John spent his ministry in Jerusalem and at Ephesus, where tradition says he was bishop. He wrote the fourth Gospel, the three Epistles that bear his name, and the Book of Revelation. Especially memorable in his Gospel are the account of the wedding at Cana (John 2:1-12), the “Gospel in a nutshell” (John 3:16), Jesus’ saying about the Good Shepherd (John 10:11-16), the raising of Lazarus from the dead (John 11), and Jesus’ encounter with Mary Magdalene on Easter morning (John 20:11-18). According to tradition, John was banished to the island of Patmos (off the coast of Asia Minor) by the Roman emperor Domitian. John lived to a very old age, surviving all the apostles, and died at Ephesus around AD 100.