Dear little one,
The Council of the Marches was a group of important people who used to meet in the past. They were in charge of a place called the "marches" which was a border area between two countries.
Just like you might have a fence around your house, these two countries had a fence that separated them. This fence was called a "border." The Council of the Marches helped make sure that everything was safe and fair on both sides of the border.
They did this by talking to each other and coming up with rules that both countries would follow. They also made sure that bad people didn't try to cross the border and cause trouble.
It was really important for the people who lived in the marches to have the Council because they knew that they were safe and protected. So, even though the Council sounds like a grown-up thing, it was really important for everyone, including kids like you!