What did the romans know about the chinese?

罗马人对中国人了解多少?


I've seen many videos on the subject regarding what the chinese knew about the Roman Empire, and their one failed mission to establish diplomatic connections with Rome.https://www.youtube.com/watch?v=koVj0GwBWt8
But I am wondering, what did the romans know? Had they even heard of an empire east of India? Did they ever try to send envoys to China aswell?

我看过很多关于中国人对罗马帝国的了解,以及他们尝试与罗马建立外交关系的一次失败的任务的视频。

https://www.youtube.com/watch?v=koVj0GwBWt8。

但我在想,罗马人知道什么?他们甚至听说过印度以东有一个帝国吗?他们是否也曾试图向中国派遣使节?