Cosa (lived 6th century)

Merchant and traveller of the 6th century. After trading in Ethiopia and parts of Asia he became a monk and wrote his Christian Topography. This work, written in Greek, is a fanciful and idiosyncratic account of the universe. It is interesting however, for certain observations made in Abyssinia (Ethiopia) and incorporated incidentally in the main argument.

He was born in Alexandria, Egypt. The Topography contains many misconceptions, such as claims that the earth is a rectangular plane, that the sun is much smaller than the earth, and that its disappearance at night is due to its revolving round a conical mountain in the north.