Quote from : The Secret Book of Revelation: The Apocalypse of St John the Divine Book

During the persecutions under the Emperor Domitian, John was summoned to Rome, where he was tortured by immersion in a pot of boiling oil and subsequently banished to the island of Patmos in the Aegean sea. It was there he wrote his Apocalypse. It was only after the death of Domitian, in A.D. 96, that he returned to Ephesus, where he was still living during the reign of the Emperor Trajan (A.D. 98-117). He became so old and frail that he could no longer walk and had to be carried to meetings and services. All he could manage to say was, "My little children, love one another." He repeated this over and over.