In ancient China, the same king was divided into "one-word king" and "two-word king". What are the differences between the two before? Personally, I feel that this should start from the history of the development of the "king".
The differentiation of the king
In the history of our country, the honorific title of the supreme ruler has changed. The kings of the Xia Dynasty were called "Hou", the kings of the Shang Dynasty were called "Emperors" (for example, the official honorific title of the King of Shang was Called Di Xin), and from the Zhou Dynasty onwards, the title of the monarch was "Wang", and after the Qin Dynasty, the emperor was emperor.
In the Zhou Dynasty, the king number could only be used by Zhou Tianzi alone. Therefore, although the barbarians of the Chu and Wu states are also called kings, they are mostly used behind closed doors, and once they encounter the strength of the Tianzi, the Chu kings and Wu kings will take their honorific titles to prevent the Tianzi from crusade.
In the Warring States period, the majesty of the Son of Heaven was absent. The princely states were called kings one after another, and eventually, the Qin king swept away the six kingdoms, and on the basis of the king, formulated a more honorable title: emperor.
After the Han Dynasty, Liu Bang synthesized the system of the Zhou Dynasty and the Qin Dynasty: while he was called emperor, he also engaged in a system of sub-feudalism, and divided a series of princes and princes--this was the beginning of the emperor's canonization of kings. However, before the Jin Dynasty, there was no difference in the title of wangjue, and the status of the one-character king and the two-character king was basically no different during this period: for example, the king of Qi was not higher than the king of Zhongshan, and the king of Hanzhong was not lower than the status of the king of Wu. However, there is such a difference: the difference in fief property determines the difference in the gold content of the king. For example, the Dai Kingdom is much poorer than the Qi State, so the Dai King is poorer than the Qi King. When Liu Bang was alive, he killed the princes with different surnames, but he did not attack Wu Rui, the king of Changsha, in the final analysis, the kingdom of Changsha was too poor.
By the beginning of the Western Jin Dynasty, there was a division of the princes.
After the establishment of the Western Jin Dynasty court, the princes were divided into two classes: princes and county kings. The prince has a higher status than the county king. This hierarchical difference continued into the Qing Dynasty.
The change of title
With the differentiation of princes and county kings, in terms of dividing the princes, there was also a difference between the one-word king and the two-word king. In general, the one-word king is often the prince, and the two-character king is often the county king. However, there are exceptions: for example, Xu Da, the king of Zhongshan in the Ming Dynasty, although the form is a two-character title, but Zhongshan, like Qi and Chu, is the name of the ancient country in the pre-Qin era, so the king of Zhongshan belongs to a special one-character king. There are also county kings whose titles have only one word, but they are actually county kings, such as Chu county kings. Although the title is a word, it is not essentially a word king.
In terms of the canonization of kings, there is still such a principle in the canonization of the one-word king and the two-character king:
The emperor's sons were canonized, mostly yizi wang, while the sons of the crown prince were mostly erzi kings: for example, when Li Jiancheng was alive, his younger brother Li Shimin was the king of Qin (belonging to the yizi king), and Li Jiancheng's sons were mostly erzi kings (county kings). If Li Jiancheng had become emperor, his sons would have ascended the throne as princes.
After Zhu Yuanzhang established the Ming Dynasty, he was afraid that the descendants of the Zhu family would suffer hardships, so he laid down a rule for the Ming Dynasty: the eldest son of the prince would inherit the title of prince in the future and be crowned as the King of Yizi. The rest of the sons were all crowned as the King of two characters. For example, the Southern Ming Yongli Emperor Zhu Youluo, because he was not the eldest son of King Gui, was crowned as the King of Yongming (二字王) by the Ming Dynasty court, and during the Southern Ming Longwu Imperial Court, Emperor Longwu considered that there was no successor to King Gui's king, so he crowned Zhu Youluo as the King of Gui. Zhu Youluo thus became the King of One Character.