A Duke (Japanese: デュークDuke) is a type of Pokémon Trainer that debuted in Generation VI. This Trainer class is a title of nobility, granted in the Battle Chateau, and Trainers with this class only appear there. Duke is the second highest rank of nobility for males, ranking above Marquis and below Grand Duke. Its counterpart for females is Duchess.
The male player character may earn the title of Duke by winning enough battles in the Battle Chateau. The male members of the Elite Four of Kalos also hold the rank of Duke in the Battle Chateau. All opponent Dukes use parties of three Pokémon, and all who are not members of the Elite Four have Pokémon at level 45 (if no Writ of Challenge is active), while Elite Four members' Pokémon are level 55.