Calamity used to think that the royal family was united; at least, there wouldn't be much suspense in the successor to the throne. After all, the King had only two suitable choices, i.e. Williams and Arthur. Other younger princes were either lack of talent or powerless due to their mother born in a humble family, so there's no chance for them to be the King's successor. Williams was born by King's lawful wife Queen Margaret, while Arthur was the eldest son born by King's concubine Lady Juliana. As a result, the crown would belong to one of them.
"Does your brother want to be the King?" When Calamity said this, she was a little scared. She really didn't want Williams to get involved in the whirlpool of the throne competition. One step wrong and there would be the end.