There are two different finds — one of them dates to the Han Dynasty, during which time maritime trade between the Roman Empire and the Chinese Empire became pretty regular, and the second find is from 2500 BC. The source here is Xinhua, so it’s an ESL success story.
There has been speculation, unfortunately probably untrue, that Roman troops captured in Crassus’ disastrous defeat by the Parthians fought against Han troops around 35 BC.
How cool would that be?!