In Arthurian legend, the Lady of the Lake is a mysterious figure who plays a crucial role in the tale of King Arthur and the Excalibur sword. She is often depicted as a magical being who provides Arthur with his sword and has connections to Merlin. Her significance lies in her role as a giver of gifts and wisdom, as well as her embodiment of the mystical qualities of the lake. She represents the connection between the supernatural and the mortal realm.