The Bosporus

The Greek name of the strait, Bósporos, “ox-ford,” from boûs, “ox,” and póros, “crossing,” the narrow channel at Byzantium joining the Black Sea to the Propontis. Polybius explains its commercial importance with precision: through this strait passed all the grain, fish, and slaves of the Black Sea, and whoever held its banks held the trade. Darius bridged it to invade Scythia, as Xerxes would later bridge the Hellespont.

The “ox-ford” is a myth fossilized in a name. The Greeks derived it from Io, the priestess of Hera whom Zeus loved and whom a jealous Hera turned into a heifer and drove in torment across the earth; in her wandering she swam this strait, which took its name from her crossing. Aeschylus has Prometheus foretell the very moment. The Greeks knew two such “ox-fords,” this Thracian Bosporus and the Cimmerian Bosporus far to the northeast, the Strait of Kerch, both named for the same heifer’s flight across the same legend.

The Latin name of the strait, Bosporus (often spelled Bosphorus by a false association with Greek phóros), taken from the Greek with its “ox-ford” sense intact. For Rome the strait gained an importance it had never had before when Constantine refounded Byzantium on its banks as Constantinople, the new capital astride the crossing between Europe and Asia, and the choke-point of the Black Sea trade became the center of an empire.

The Latin carried the name into the European languages, and the spelling Bosphorus, with its intrusive h, became common, as though the name held the Greek for “light-bearer” rather than “ox.” But the ox is the older truth: like the Hellespont, the Bosporus is a strait of vast strategic weight bearing a name from a slight and ancient myth, the crossing of Io the heifer. Two narrow waters, two girls of legend, one made a cow and one fallen from a ram, between them guard the whole sea-road to the north.