According to tradition, St. John the Apostle was assisted by St. Prochoros in writing the Gospel According to St. John. St. John, "Son of Thunder" (Mark 3:17), was one of the Twelve Apostles of Jesus. John and his brother, the Apostle James, were fishermen by trade, like their father Zebedee. John is believed to be the youngest Apostle and also "the beloved disciple" of Christ (John 13:23; 21:7,20). On the Cross, Jesus entrusted His mother, the Virgin Mary, to John's care (John 19:26, 27). John was a "pillar" of the church in Jerusalem, and later moved to Ephesus. He served as the leading authority ("Elder," lit. "presbyter," in 2 John 1) of Ephesus for the remainder of his ministry. During the reign of the tyrannical Roman Emperor Domitian (A.D. 81-96), John was exiled to the nearby island of Patmos, where he wrote Revelation (also called the Apocalypse). Upon the emperor's death he returned to Ephesus to resume his episcopacy and to write his Gospel.
John is the first of only three saints in history to be named by the Church "the Theologian," because of the profundity of his Gospel, which has been called "the spiritual Gospel." The new Testament contains four other books attributed to John: three letters (1, 2, and 3 John, written about 90 A.D., and the Book of Revelation, written about 95 A.D.
St. John the Apostle was almost one hundred years old when he died, about 96-100 A.D.
from The Orthodox Study Bible
Copyright © 1993 by St. Athanasius Orthodox Academy,
Nelson ISBN 0-8407-8391-4