The prince was originally a kid from the streets before he gave himself up to the search of the prince aka. him. He befriends the dark hair dude who is also one of the kids the king takes in because they are beautiful. The king is a pedophile (takes the kids to his chamber to "read to them" *cough cough* takes advantage). The prince is now living and trying to become king, the dark haired guy now secretly is supporting him and knows he is a true king. Thus he is doing what he can to help the prince become king and teach him the important stuff along the way.
King's Maker