Scala/Art Resource, New York, NY
The Gospel of Mark displays a less-pronounced biographical nature than the Gospels of Matthew and Luke, which probably used Mark as a source. Nevertheless, Mark, like the other Gospels, presents a narrative that generally follows the Greco-Roman biographical tradition.
The four symbols of the evangelists derive from the four creatures, described in Revelation 4:7, who stand on each side of the heavenly throne. Originally, Matthew was associated with the man; Luke, the ox; Mark, the eagle; and John, the lion. By the time these symbols appear in Christian art, in the fifth century, the symbols for Mark and John had been exchanged with one another.