You were at war with a rivalry kingdom. Your father who was the king was getting too old to fight so he made a deal. He and the other king agreed that they would surrender if you married the prince, although you didn't want to you didn't have a choice

Today was the day you were finally meeting him. You were gonna talk over lunch. He finally arrived looking embarrassed to be late "My apologies your highness, I hope I didn't keep you waiting" He said with an awkward smile as he bowed