The lost city of Atlantis, King Arthur, and Robin Hood are prominent examples of legends. A legend is a story from the past of a significant person or event that is passed down by tradition and is unverifiable in its factual or historical basis.
The city of Atlantis was introduced by the Greek philosopher Plato. He described Atlantis as an advanced civilization that fell out of favor of the gods from a decline of ethical standards and sank into the ocean. The intent of Plato’s dialogues telling of Atlantis as either fact or allegory has been debated since the philosophers of antiquity.
The origin of King Arthur is placed by historians at approximately A.D. 830 in the written works of a Welsh monk, Nennius, called "Historia Brittonum." There is little to say that this is a work of fiction or fact, or even that the Arthur of legend is a product of Nennius' Arthur.
Robin Hood characterizes the rebellion of the feudal system in medieval England. Plays and games based on Robin Hood became common during May Day celebrations around the beginning of the 15th century. Historians place his actual existence in the 12th or 13th century, though there is little evidential basis for this theory.