According to the Vietnamese dictionary, the words Emperor, monarch, and king are synonyms/nearly meaning “The head of the monarchy state, often ascending to power by way of succession”. More clearly, the king/king is “the king of a country” and the emperor is “the king of a large country, often being subordinated to by many surrounding countries”.
The emperor often claimed to be the son of heaven or the only person who was endowed with power by the will of God. The emperor could also bestow other kings with titles or handle disputes between kingdoms. The emperor is considered the “king of kings”.
For example, in the case of the king of our country, he proudly proclaimed himself emperor in the poem “God” by Ly Thuong Kiet: “Nam Quoc Son Ha Nam De settled”. In later generations of our country, most of the posthumous titles used the title of emperor, like the kings: Dinh Tien Hoang is Dai Thang Minh Emperor, Ly Thai To is Than Vu Emperor, Tran Thanh Tong is Emperor Tuyen Hieu. , Le Thanh Tong is the Thuan Emperor, Quang Trung is the Emperor Vu, Gia Long is the Emperor Cao…
Therefore, in order to distinguish between kings and emperors, it is necessary not only to rely on dictionary definitions but also to consider the historical, cultural and political context of each country and period. This is not a simple job, but also very interesting and useful.