Shortly after the events of The Legend of Zelda, Link notices a strange mark on the back of his left hand, similar to that of the crest of Hyrule. He seeks out Impa, who responds by taking Link to the tower of Hyrule castle, where a maiden lies in a deep sleep. Impa tells Link that the maiden is Zelda, the princess of Hyrule from long ago, and the origin of the "Legend of Zelda." A wizard had cast a sleeping spell on her, which also resulted in his own death. The prince, being unable to reverse the spell, had his sister placed in the castle tower, in the hope that she would one day be awakened. He decreed that all females born to the royal family from that point on would be named Zelda, in remembrance of this tragedy.
Impa says that the mark on Link’s hand means that he is the chosen hero to awaken Zelda. She gives Link a chest containing six crystals and ancient writings indicating that each crystal needs to be placed in a different palace in Hyrule. This will open the way to the Great Palace, which contains the Triforce of Courage, which has the power to awaken the enchanted Zelda. Taking the crystals, Link sets out to restore them to their palaces. Meanwhile, the followers of Ganon are seeking to kill Link; if they sprinkle his blood on Ganon’s ashes, it would bring Ganon back to life.
Ultimately, Link restores the crystals to the six palaces, and with the crystals in place, the entrance to the Great Palace is opened. After venturing deep inside, Link is made to battle a shadowy doppelgänger of himself known as Dark Link. Link then claims the Triforce and returns to Zelda, who awakens and embraces Link.