Im not 100% sure but I think there is two options
1)the prince’s country was absorbed by the empire
2) the prince he is a relative of the current emperor (possibly nephew). The current emperor killed his older brother so he would have a chance to pursue his childhood love.
ohh tyy
If I'm not mistaken Sofen used to be a Kingdom, subdued by Kaleid under the order of the Emperor then became a part of the Empire and now Kaleid ruled over them as Grand Duke. Kaleid killed all the royal family of Sofen Kingdom, but the Prince survived by sacrificing his stand in.
Thank you
where the heck did that prince come from
wasn’t the king single?? and in love with his maid/childhood friend?? and rlly young?? is he from another country or smth