There are mainly two kinds of kings, commonly known as "one-character king" and "two-character king", and the position of one-character king is much more noble than that of two-character king.

In fact, we can understand it this way: the position of the word Wang is "Wang" (actually called "Prince") and the position of the word Wang is "County King".

At the beginning, all fiefs were actually fiefs. The production, taxation, military and political affairs of the fief are all owned by the fief, and the central government has only the right to supervise. However, after the rebellion of the vassal king in the Han Dynasty, the actual fief was rarely given to the "king", only as an honorary title, reflecting the wage level. These kings either live in the central government, enjoy honorary titles and salaries, or live in fiefs, but they have no jurisdiction over the localities. Instead, they were monitored by local officials to prevent riots (as in the Ming Dynasty).

A word king, written as prince. Most of them take the name of the ancient Zhou Dynasty as a symbol to show their respect for the Zhou rites (which is basically the case in feudal society), such as Qin Wang, Wu Wang, Wang Jin, Rebecca, Liao Wang, Dai Wang and Shu Wang. So the title of "King of England" is ridiculous.

The word king, written as county king. Most of them are named after counties, such as warrior Lan Ling (the fief is in Lan Ling), Xiangyang King (the fief is of course in Xiangyang) and Yanping King (the fief must be Yanping). In fact, their titles should be exactly four words, calling Lanling County King, Xiangyang County King and Yanping County King all accurate.

Of course, there are special circumstances for sealing the king, but since it is called "special circumstances", it is of course special and rare:

1, with the army as the number, such as the king of the day (Wu Sangui).

2, pinning their wishes, such as the "axe king" killed by Li Zicheng in the late Ming Dynasty.

3. Kindness (this is mainly in the Qing Dynasty, but the word "pro" is usually called out in the middle), such as Prince Yong (Yin Zhen). We can know that this person's personality was very calm when he was a prince, so he got the word "Yong", and then as Prince Yi (Huang Hong), we can know that this person's personality is very easy-going and approachable. Although, these may be their masks in front of the emperor.

I wonder if these can help you. Please keep in touch with me if you have any questions.