Lone Young Boy

The Lone Young Boy is a character mentioned in the prologue of The Legend of Zelda: Four Swords. Vaati, the Wind Sorcerer was terrorizing Hyrule, kidnapping young maidens and felling anyone who challenged him. Until the Lone Young Boy appeared wielding the Four Sword. Using the Four Sword to split himself into four, he defeated Vaati and sealed the Wind Sorcerer inside the blade. The young women explained what had happened but the people did not believe one so young could succeed when so many brave knights failed. Nevertheless they enshrined the Four Sword and protected it for generations. The Lone Young Boy disappeared and was never heard from again.

Theory
It is possible the Lone Young Boy is an incarnation of Link, more specifically the incarnation of Link that defeats Vaati in The Legend of Zelda: The Minish Cap. However, a number of inconsistences arise if this is to be true. Most notably in The Minish Cap Link does not properly split into four and he seemingly kills Vaati instead of sealing him away. Zelda is also the only Maiden Vaati kidnaps and only briefly at the end of the game. Most of Hyrule also don't react to Vaati's presence with any great sense of panic as Vaati impersonates King Daltus and is not actively causing trouble for most of the game. However it is said that the people of Hyrule were disbelieving of the initial story meaning, over time, the legend could have changed to make Vaati seem more dangerous and Link's accomplishment greater.