My current WIP is about a princess who runs away from an arranged marriage and by doing so destabilizes the political position of her family. So her brother the prince goes out to find her. But as I started developing the backstory as to why their political position was so weak, I found the backstory to be a bit more compelling. The family has come into power by dubious means. The father was a ward of the previous ruler who died recently. He made a promise to the ruler that he would protect the heir (who's nine). The father then decided to take the position himself which caused a rebellion from the supporters of the previous ruler, led by his brother. Long story short, the resulting war caused a lot of damage and weakened the kingdom greatly, which is why the princess's marriage was so important. The story about the rebellion seems a bit stronger than the princess story so I'm not whether to make that the main story or just keep it as backstory for the characters and setting. Suggestions?