<P> The Weilüe by Yu Huan (c. 239--265 AD), preserved in annotations to the Records of the Three Kingdoms (published in 429 AD by Pei Songzhi), also provides details about the easternmost portion of the Roman world, including mention of the Mediterranean Sea . For Roman Egypt, the book explains the location of Alexandria, travelling distances along the Nile and the tripartite division of the Nile Delta, Heptanomis, and Thebaid . In his Zhu Fan Zhi, the Song - era Quanzhou customs inspector Zhao Rugua (1170--1228 AD) described the ancient Lighthouse of Alexandria . Both the Book of the Later Han and the Weilüe mention the "flying" pontoon bridge (飛 橋) over the Euphrates at Zeugma, Commagene in Roman Anatolia . The Weilüe also listed what it considered the most important dependent vassal states of the Roman Empire, providing travel directions and estimates for the distances between them (in Chinese miles, li). Friedrich Hirth (1885) identified the locations and dependent states of Rome named in the Weilüe; some of his identifications have been disputed . Hirth identified Si - fu (汜 復) as Emesa; John E. Hill (2004) uses linguistic and situational evidence to argue it was Petra in the Nabataean Kingdom, which was annexed by Rome in 106 AD during the reign of Trajan . </P> <P> The Old Book of Tang and New Book of Tang record that the Arabs (Da shi 大 食) sent their commander Mo - yi (摩 拽, pinyin: Móyè, i.e. Muawiyah I, governor of Syria and later Umayyad caliph, r . 661--680 AD) to besiege the Byzantine capital, Constantinople, and forced the Byzantines to pay them tribute . The same books also described Constantinople in some detail as having strong granite walls and a water clock mounted with a golden statue of man . Henry Yule noted that the name of the Byzantine negotiator "Yenyo" (the patrician John Pitzigaudes) was mentioned in Chinese sources, an envoy who was unnamed in Edward Gibbon's account of the man sent to Damascus to hold a parley with the Umayyads, followed a few years later by the increase of tributary demands on the Byzantines . The New Book of Tang and Wenxian Tongkao described the land of Nubia (either the Kingdom of Kush or Aksum) as a desert south - west of the Byzantine Empire that was infested with malaria, where the natives had black skin and consumed Persian dates . In discussing the three main religions of Nubia (the Sudan), the Wenxian Tongkao mentions the Daqin religion there and the day of rest occurring every seven days for those following the faith of the Da shi (the Muslim Arabs). It also repeats the claim in the New Book of Tang about the Eastern Roman surgical practice of trepanning to remove parasites from the brain . The descriptions of Nubia and Horn of Africa in the Wenxian Tongkao were ultimately derived from the Jingxingji of Du Huan (fl . 8th century AD), a Chinese travel writer whose text, preserved in the Tongdian of Du You, is perhaps the first Chinese source to describe Ethiopia (Laobosa), in addition to offering descriptions of Eritrea (Molin). </P> <P> Some contact may have occurred between Hellenistic Greeks and the Qin dynasty in the late 3rd century BC, following the Central Asian campaigns of Alexander the Great, king of Macedon, and the establishment of Hellenistic kingdoms relatively close to China, such as the Greco - Bactrian Kingdom . Excavations at the burial site of China's first Emperor Qin Shi Huang (r . 221--210 BC) suggest Greek stylistic and technological influences in the artworks found there, including the famous terracotta army . Cultural exchanges at such an early date are generally regarded as conjectural in academia, but excavations of a 4th - century BC tomb in Gansu province belonging to the state of Qin have yielded Western items such as glass beads and a blue - glazed (possibly faience) beaker of Mediterranean origin . The only well - known Roman traveller to have visited the easternmost fringes of Central Asia was Maes Titianus, a contemporary of Trajan in either the late 1st or early 2nd century AD who visited a "Stone Tower" that has been identified by historians as either Tashkurgan in the Chinese Pamirs or a similar monument in the Alai Valley just west of Kashgar, Xinjiang, China . </P> <P> The historian Florus described the visit of numerous envoys, including the "Seres" (possibly the Chinese) to the court of the first Roman Emperor Augustus (r . 27 BC--14 AD): </P>

Where were the roman and chinese empires located