A canon of kings is a big list of all the rulers who have led a certain place or people throughout history. It's like a really long family tree for a group of rulers.
Think of it like this: just like you have a family tree that shows all your ancestors and who came before you, a canon of kings shows all the rulers of a place or people, and who was in charge before them.
The name "canon" comes from a type of rule or law that says what should be included in the list and how it should be organized. So a canon of kings is a rule or law that says what should be included in the list of rulers and how they should be ordered.
These lists can be important for historians or people who are interested in learning about history because they help us understand how different rulers impacted a place or people over time. They can also help us see patterns and trends in how rulers governed, and how they were chosen or replaced.