The former king of Tatrama is Roy's real father. Though Roy himself doesn't know about it.
The former king asked a villager who was close with Roy's mother to raise Roy in the village and act as Roy's father. And to not let anyone know that Roy is the king's son. Because there will be too many problem if it was known.
The former king of Tatrama was known to be loyal to his wife, the former queen. And so, not only will Roy's existence will make the people lost their trust in him. There will be many political enemies to target Roy if he was known.
That's why the king asked Roy's mother, her close friend, and the village chief to keep it secret. At least until Roy awakened his magic.
"Wait, what?! He's your father? The former king of Tatrama? And Roy is his illegitimate child?!" Victoria was shocked to hear that.