Gustaf

King Gustaf is a minor character in The Minish Cap. In the game, he is a ghost, but he was once king of Hyrule. This makes him the ancestor of its current King Daltus and Princess Zelda.

He first appeared to Link after he retrieved the Water Element from the Temple of Droplets. He marks his grave on Link's map and requests that he come visit. When Link arrives, Gustaf gives him a gold Kinstone that will open a stone door in Veil Falls. This allows Link to reach the Cloud Tops, which leads to the Wind Element.

Timeline Speculation
Though Gustaf plays a relatively minor yet pivotal role in The Minish Cap, some groups of theorists believe him to be very important to the timeline of the entire series. Prior to the release of The Minish Cap, most fans of the series universally  agreed that Ocarina of  Time was the true first game in the timeline of the series due  to its inclusion of the origin stories of such elements as the Triforce, Ganondorf, the establishment of  Hyrule as a kingdom, and the  origin story of the Sacred  Realm/Dark  World. Since the release of The Minish Cap however, a fraction of the Zelda community have for several good reasons come to  believe that The Minish Cap precedes Ocarina of Time  chronologically. However, another group argues that it is Gustaf himself who seemingly voids this argument by stating that he ruled Hyrule as king "countless ages ago",  indicating that Hyrule has, at that point, existed as a kingdom for many  ages. This is in stark contrast to Ocarina of Time, where it is established that Hyrule has only  existed as a kingdom for roughly a decade at the opening of the story as  a result of the bloody Hyrulean Civil War  that left the Hero  of Time an orphan. Thus, though Gustaf plays a relatively small role in the events of The Minish Cap, his very  inclusion in the story of The Minish Cap, combined with his remarks,  casts significant doubt upon the possibility of The Minish Cap  preceding Ocarina of Time. Others argue that the interpretation of the King's words is disputable, and that there is no concrete proof.