the Aral Sea), Zemarchus sent off an express messenger, one George, to announce his return to the emperor. George hurried on by the shortest route, "desert and waterless", apparently the steppes north of the Black Sea, while his superior, moving more slowly, marched twelve days by the sandy shores of the lagoon. He crossed the Emba, Ural, Volga, and Kuban (where 4000 Persians vainly lay in ambush to stop him), and passing round the western end of the Caucasus, arrived safely at Trebizond and Constantinople. For several years this Turkic alliance subsisted, while close trade was maintained between Central Asia and Byzantium (when another Roman envoy, one Valentinos, went on his embassy in 575 he took back with him 106 Turks who had been visiting Byzantine lands) but from 579 this friendship rapidly began to cool. It is curious that all this travel between the Bosporus and Transoxiana seems not to have done anything to correct, at least in literature, the widespread misapprehension of the Caspian Sea as a gulf of the Arctic Ocean. See also Chronology of European exploration of Asia Notes Further reading pp. 128–131 6th-century Byzantine people Byzantine diplomats People of the Roman–Sasanian Wars Explorers of Central Asia Western Turkic Khaganate Silk Road 6th-century diplomats