During Vietnam's monarchial period, the Vietnamese nobility (quý tộc) were classified into eleven ranks (tước vị), with names similar to their Chinese equivalent.
This occurred due to Chinese suzerainty over Đai Viet leading to the concept of “Emperor at home, King abroad”.
In the context of Vietnamese historical records this used to refer to the successor to the Emperor thus making it equivalent to a Prince in the Western feudal system.
[3] The use of noble titles has existed in China since ancient times and the system of nobility used in Vietnam until 1945 dates back to the Zhou dynasty (nhà Chu).
[4] While no protocol has regulated the matter of these designations, over 50 years of use have definitively enshrined these terms for translating Vietnamese noble titles.