Imagine Batman in Medieval Europe circa 1459, suited in full plate mail armor and ready to bash in the faces of evildoers with his gauntleted fists. Artist Igor Kieryluk has, with a set of concept art titled Gotham 1459. Granted, the Dark Knight would probably not be as acrobatic and agile in all that heavy armor (he can forget about scaling castle walls with a grappling hook). Perhaps as a wealthy lord he would be able to secure the help of a mysterious alchemist to develop something more flexible and lightweight.
Check out some other classic characters reimagined for the 15th century.