In Skyward Sword, what is the base sword that later becomes the Master Sword?

In Skyward Sword, the Goddess Sword is the base blade that later becomes the Master Sword.

Link first receives the Goddess Sword from the statue of the goddess Hylia in Skyloft. The sword contains Fi, a sentient spirit who guides him and helps explain the weapon’s purpose. At this stage it is not yet the familiar Master Sword seen in many later Zelda stories.

During the game, Link strengthens the blade by completing trials and obtaining three Sacred Flames connected with the ancient goddesses. These flames purify and upgrade the Goddess Sword. Zelda’s role as the mortal reincarnation of Hylia is also central to the transformation: her power helps grant the blade its completed form, the Master Sword.

The change is part of Skyward Sword’s larger role in Zelda chronology. The game is set at the beginning of the series’ timeline and presents an origin story for the recurring sword, Link’s heroic cycle, and the conflict connected with Demise. The Great Fairy’s Sword, Four Sword, and Kokiri Sword belong to other parts of Zelda lore and are not the precursor identified in this game.