According to legend, Saint John was exiled to Patmos during the persecutions under Emperor Domitian. There, he is thought to have written the Book of Revelation, although some attribute the authorship of Revelation to another man, called John the Presbyter, or to other writers of the late first century AD. In the painting, John is depicted sitting on a rock by the sea, in the process of writing the Book of Revelation. Next to him there sits an eagle, John's commonest attribute along with a book or scroll.
