Ancient history

In the story of King Arthur how did sword get in rock first place?

In the story of King Arthur, the sword Excalibur was not the one that was embedded into the stone: in the legends, the sword Excalibur was given to Arthur by the Lady of the Lake. The one that was set in the stone was previously belonged to Uther Pendragon, Arthur's father, and was put there by Merlin.