Batman is arguably the most famous superhero in the world of written fiction. His backstory and exploits are well-known by the mainstream public. Robin, his mentee, is arguably the most famous sidekick of all time. There have been several iterations of the character, but Robin was first introduced as Dick Grayson, an acrobat prodigy in The Flying Graysons. His family is tragically murdered while performing in the Gotham City Circus, and Bruce Wayne/Batman takes the young Grayson under his wing as his crime-fighting sidekick.