British scholar Timothy Mitford believes he has found the spot from which a Greek army first sighted the Black Sea during its flight from the forces of the Persian king Artaxerxes II in 401 B.C. Earlier that year Artaxerxes had defeated his brother Cyrus at Cunaxa on the Euphrates, crushing the latter's bid for the throne. Among Cyrus' forces was a contingent of Greek mercenaries known as the Ten Thousand, led by the Athenian general and historian Xenophon, who recounts the event in his Anabasis. After the battle Xenophon led his troops through the Tigris and upper Euphrates valleys,...