In ancient monarchies, the rank of the emperor was often considered higher than that of the king for the main reasons for this:
1.Historical status and cultural traditions: In some ancient civilizations, such as ancient China and the Roman Empire, the title of emperor often has a longer history and higher symbolic meaning. Emperors are often seen as representatives of theocracy or authorized persons to receive theocracy, with a higher divine and ruling status. In contrast, the position of a king may have emerged at a later stage in history, or he may have ruled within a smaller territorial confines and was therefore often secondary in status.
2.Territorial scope and ruling power: In some empires or large unified states, the emperor tends to rule a wider territory, with greater ruling power and more resources. This advantage in geographical and political power also made the emperor's status higher in the hierarchy.
3.Succession system and legal status: In some civilizations, the system of succession of emperors may be stricter or formal, with more stable succession rules or laws determining the successor of the emperor. In contrast, the succession of kings may be more susceptible to controversy or challenge by local rulers, leading to the instability of the king's position and thus reducing his status in the hierarchy.
4.Religious or philosophical ideas: In some civilizations, the status of the emperor is given a higher religious or philosophical significance, and is seen as the representative or implementer of the cosmic order. For example, in Chinese Confucianism, the emperor is considered the son of the Mandate of Heaven and represents the connection between heaven and earth, with a supreme status. In other civilizations, similar religious or philosophical ideas can also affect the difference in hierarchy between emperors and kings.
It is important to note that the definitions and status of emperors and kings may vary from civilization to civilization and historical period, and the above reasons may not apply in all cases. In some cases, the status of the king may be equal to or higher than that of the emperor, depending on the political, religious, cultural, and historical factors of the time.