When you create a fictional multiverse as rich and diverse as that of Zelda's then deciding what is and isn't canon can be a tricky process (as was evidenced when one of our former staffers got into a particularly heated debate with Nintendo PR about the Zelda timeline at an official press event many moons ago).
The franchise has been around for years and during that time sequels, spin-offs, localisations and side-projects have all added to the lore, making it hard to decide on the "complete" story of Link and his battle against Ganondorf (or Ganon, if you prefer).
One thing which is apparently now officially rubber-stamped is Ganondorf's last name. According to the official Zelda site, his second name is Dragmire - something which had previously been revealed many years ago in the English manual for The Legend of Zelda: A Link to the Past but was never considered to be 100 percent fact until now:
Once known as the King of Thieves, Ganondorf Dragmire used the power of the Triforce to become the beast, Ganon.
It's great to see the Zelda universe being comprehensively fleshed out in this fashion, but the real reason to celebrate this is that Dragmire is a badass second name.