Oooh! Nice to know someone else is a sucker for royal characters aswell. I have around 6 or so kings, but Caspian is my favorite so I'll share.
(Warning: Death and mental illness is mentioned. And im bad at explaining so im sorry shshs)
(Also, this is set in the 1750s)
Basically, Caspian was born the heir of the Western kingdom in a land called Irisan. (The land is seperated into four seperate kingdoms. Northern kingdom, Southern kingdom.. you get the gist.) He's a nice, and caring king.. but he's much too mentally impared to be able to run his kingdom affectively. He has schizophrenia, so he has a hard time telling what's real and what isn't, and is constantly stuck inside of his head. He lost both parents, and practically everyone else that lived in his kingdom in a massacre plotted by an enemy of his father, causing him to be crowned king, as well as being left an orphan by age 11. From then on, the town of the western kingdom has been a ghost town. Everyone fled, since the fear of being targeted aswell was too great. For an entire decade, he practically raised himself. (with the help of the other kingdoms aswell. They'd provide him food and check up on him every once in awhile to make sure he was alive)
Because he was practically abandoned and isolated himself for an entire decade, now he has major attachment issues. He clings onto anyone 'real' as if his life depends on it.
Luckily, in modern day, he's married and lives a happy life with his husband ,who also happened to be a king.
That's all! Thank you for letting me ramble. Caspian is my ultimate favorite oc and its so nice getting to talk about him >') I hope my explanation makes some sense