Zemarchus Zemarchus ( , fl . c . 568 ) was a Byzantine official , diplomat and traveller in the reign of Justin II . In the middle of the 6th century , the Göktürks conquered the Sogdiana and thus gained control of the silk trade , which then passed through Central Asia into Sassanid Persia . The Persian king , Chosroes I , dreading the intrusion of Turkish influence , refused to allow the old commerce to continue . The Turks , after many rebuffs , consented to a suggestion made by their mercantile subjects of the Soghd , and in 568 sent an embassy to Constantinople to form an alliance with the Byzantines and commence the silk trade directly with them , bypassing the Persian middlemen . The offer was accepted by Justin II , and in August 568 , Zemarchus the Cilician left Byzantium for Sogdiana . The embassy , whose description is preserved by Menander Protector , was under the guidance of Maniakh , chief of the people of Sogdiana , who had first , according to Menander , suggested to Dizabul Istämi ( Sizaboulos in Greek sources ) , the great khan of the Turks , this Roman alliance , and had himself come to Byzantium to negotiate it . On reaching the Sogdian territories the travellers were offered iron for sale , and solemnly exorcised ; Zemarchus was made to pass through the fire ( i . e . between two fires ) , and strange ceremonies were performed over the baggage of the expedition , a bell being rung and a drum beaten over it , while flaming incense - leaves were carried round it , and incantations muttered in Scythian . After these precautions the envoys proceeded to the camp of Dizabul ( or rather of Dizabul ' s successor , him having just died ) in a hollow encompassed by the Golden Mountain , apparently in some locality of the Altay Mountains . They found the khan surrounded by astonishing barbaric pomp - gilded thrones , golden peacocks , gold and silver plate and silver animals , hangings and clothing of figured silk . They accompanied him some way on his march against Persia , passing through Talas or Turkestan in the Syr Daria valley , where Hsuan Tsang , on his way from China to India sixty years later , met with another of Dizabul ' s successors . Zemarchus was present at a banquet in Talas I where the Turkish kagan and the Persian envoy exchanged abuse ; but the Byzantine does not seem to have witnessed actual fighting . Near the river Okh ( possibly Syr Darya ) he was sent back to Constantinople with a Turkish embassy and with envoys from various tribes subject to the Turks . Halting by the vast , wide lagoon ( possibly , 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 ; 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 Turkish alliance subsisted , while close intercourse was maintained between Central Asia and Byzantium ; when another Roman envoy , one Valentinos , goes on his embassy in 575 he takes 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 .