Erythraean Sea

Map showing the Erythraean Sea off the Horn of Africa. Drawn by James Rennell, 1799.

The Erythraean Sea (Greek: Ερυθρά Θάλασσα; Erythra Thalassa) is one of the names found in ancient cartography. This name may have derived from the seasonal blooms of the red-coloured Trichodesmium erythraeum near the water's surface, as the Greek "Ερυθρά" actually means "red".

In the third century, Flavius Philostratus made this comment: "And they say that the sea called Erythra or "red" is of a deep blue colour, but that it was so named, as I said before, from a King Erythras, who gave his own name to the sea in question."

Use of the name

The name 'Erythraean Sea' has been or is still used for the following places:

• As a name for the Red Sea, especially after the 19th century. The modern country of Eritrea was named after this ancient Greek name.
• In centuries past the name 'Erythraean Sea' was applied by cartographers to the whole NW part of the Indian Ocean, mainly the area around Socotra, between Cape Guardafui and the coast of Hadhramaut. This name has now become obsolete and the name Gulf of Aden is presently used, although for a smaller area. In maps where the NW Indian Ocean is named thus, the Red Sea appears as "Arabian Gulf". In the Periplus of the Erythraean Sea, as well as in some ancient maps, the name of the sea refers to the whole area of the northwestern Indian Ocean, including the Arabian Sea.
• In the opening sentences of Herodotus's history he refers to the Phoenicians having come originally from the Erythraean Sea.
• The name "Erythraean Sea" was used as well to refer to some gulfs attached to the Indian Ocean, specifically, the Persian Gulf
• Nowadays the name is applied to a large dusky region on the surface of planet Mars, known as Mare Erythraeum.

See also

• Periplus of the Erythraean Sea
• Mare Erythraeum