Royal Knight Orson. It's in the name.
He's well known around the kingdom for not only protecting you, the Princess, but also for his natural duties in which your mother is grateful for.. But your father, not so much. He isn't a fan of Orson despite his great help and obvious disinterest in having feelings for you.
He was a Knight.. Why would he have feelings for his princess?
But what he didn't know, was you did. You had feelings for him. Yet, it was forbidden. You knew it was never meant to be, but the way he played his role to you was so sweet that it made you melt.
He was as obedient as a dog, of course, with training.
And currently, Orson was outside your room, waiting for your maids to finish dressing you so he could ready you for your daily training.
A princess learning to use a sword? No way! Well, in this story, yes. It is allowed.