We know about Marco Polo and other european traders and missionaries going to China, but was there anything like that in the reverse? I'm looking at the historical period from the fall of the Western Roman Empire to the 1500s.
For example, would there have been Chinese mercenaries in Byzantium akin to the Varangians? Would there have been a 'Chinese quarter' in Byzantium much like the Latin Quarter? Would there have been Chinese traders in Byzantium or medieval Venice or Florence or Rome or Kiev?
Whilst I am by no means a historian, I am a Chinese (I live in Hong Kong) who is very interested in Roman history (particularly the early Roman Republic and the Punic Wars), so I hope my post would be acceptable.
A Han dynasty diplomat, 張騫 (Zhang Qian) basically pioneered land trade and diplomatic relations between the far east and the West, Zhang Qian almost went as far as Parthia during ~120 BCE and also heard tales about the Roman republic during his journey. In his own report, he detailed several power players in the region including the Romans (Da Qin), the Parthians (An Xi) and the Kushans (Guishuang).
After Zhang Qian's journey, numerous envoys from both sides were sent over the years with varying success, at one point, the Roman historian Florus mentioned emissaries from the far east empire known as the "Seres" that established an embassy in the early Roman empire. Many people theorised that Seres is in fact, China.
Relations are held and trade (often indirectly) continued throughout the times and is popularly known as the Silk Road as the Romans (by extension the Byzantines) and Parthians are rabid for silk.