An example would be the Shu Dynasty where Emperor Liu (Luu) Bei's descendents left their capital in Si Chuan after losing to Wu and Wei dynasties and eventually escaped to Vietnam.
An example would be the Shu Dynasty where Emperor Liu (Luu) Bei's (劉備) descendents left their capital in Si Chuan. After losing to Wu and Wei dynasties in the Three Kindgom Era, many royalties and peasants alike headed south and eventually escaped to Vietnam.