Avalon (DC Comics)

Avalon is a fictional planet in the 30th Century of the DC Universe. Ruled by a king and served by knights bearing weapons shaped like oak branches, the planet exists in a medieval stage of technology. The King's rule was challenged by a wizard calling himself "Lord Romdur", who turned out to be Mordru in disguise. The Legion of Super-Heroes visited the planet, where Star Boy used his mass-inducing powers to collapse Mordru's castle, burying him alive. He remained there until freed by Darkseid.