Why Serbia and China are hardcore brothers?

Recently, a topic with the keyword # SERB # has frequently appeared on Weibo searches. Many friends only learned about it because of the epidemic. It turns out that China still has such a hardcore brother in Europe. In fact, the origin of Serbia and China can be traced back decades.

The full name of Serbia today is "The Republic of Serbia", which was founded in 2006, but why is it said that it has decades of history with China? Because this "old" and "young" country was once another country known to the older generation of people called Yugoslavia.

Yugoslavia is the general term for several countries established on the Balkan Peninsula from 1929 to 2003. The Yugoslav Federation was founded on the basis of the Kingdom of Serbia established by the Serbian tribe independent from the Ottoman Turkish Empire.