Okay kiddo, a sacred king is like a special person who is chosen to be the leader of a group of people. They are called sacred because they have a special relationship with the gods or spirits that the people believe in. The king is responsible for lots of things, like making sure there is enough food and water for everyone, protecting the people from enemies, and making sure everyone follows the rules.
The idea of a sacred king comes from a long time ago when people believed that their leaders had special powers that came from the gods. They believed that the king was chosen by the gods to rule over them and that he was connected to them in a special way. This meant that the king was more important than other people and had to be treated with respect.
Sometimes the sacred king would have to do special ceremonies or rituals to show that he was connected to the gods, like wearing special clothes, carrying a special staff, or performing sacrifices. The people would also have to follow special rules or taboos to make sure they didn't offend the gods and bring bad luck to the kingdom.
Overall, the sacred king was a very important person in ancient societies, and he symbolized the connection between the people and the gods.