If your father is a prince, then you are the heir of your son. If your father is not dead, your position is the prince. If you have many brothers, then you have to compete with them for the position of prince. Generally speaking, the eldest son is called Prince. At first, the prince was just a title. Later, it evolved into a title, later called Chu Jun, who inherited his father's eldest son. However, for example, Zhou Xuanwang made the second son of Duke Wu of Lu a prince, which eventually led to civil strife in Lu. Later generations called the official title of the heir to the title of prince prince, which was mostly filled by Di and Chang. The third time in the history of the Eastern Zhou Dynasty: "Send someone to the State of Zheng to report the death of Zheng Bo to the Prince and teach him to take revenge." At the beginning of the Han Dynasty, the official title of the legal heir of the Prince was Prince, and later, in order to distinguish it from the Crown Prince, it was changed to Prince, and the descendants did not change it. In addition, the sons of nobles and senior officials are also customarily called princes to show respect, but this is not a formal title. Of course, even the position of the duke can be passed on to the next generation. Moreover, as long as this dynasty still exists, if their descendants ever had a duke, it means that the status of this family is more important.