Prince of Hyrule

Very little is known about the Prince of Hyrule. He is only mentioned in the Adventure of Link, where it says that he was partly responsible for putting Princess Zelda in a coma. Although he isn't actually seen in the game, artwork of him was shown in the manual.

Biography
His father was the King who had ruled Hyrule and maintained peace with the Triforce. After his father died, the prince had been looking all over for the Triforce, but was tricked by the Magician who was close to his father, telling him that the King told the Prince's sister, Princess Zelda, about the Triforce.

After Princess Zelda refused to tell him when he questioned her, the Magician then angrily threatened to place her in an eternal sleep if she didn't tell him. After she refused The Magician, he used his remaining life force to place a spell on her and immediately died.

In honor of her, the prince announced that all females born into the Royal Family of Hyrule must bear the name "Zelda".