from The Fourth Book of the Christian Topography of Cosmas Indicopleustes. websource
Andrew Wiesner explains: "Cosmas, a sixth century native of Alexandria, spent the earlier years of his life as a seafaring merchant. He traveled extensively during this time, and his surname would suggest that his travels extended as far as India. He eventually retired from commercial enterprises and gave himself over to the monastic life, probably among the Nestorians. During this phase of his life he composed treatises on geography, cosmography, and scriptural exegesis. The Christian Topography is the only one of his works to have survived, and contains treatments of all of these topics."