Horace (Harry) Derwent
Derwent is a multimillionaire playboy with connections to organized crime, particularly in the gaming industry in Las Vegas Nevada. He owns the Overlook in 1945 when the masked ball goes down, and is responsible for the hotel's renovation, including the roque court. We aren't sure if Derwent is alive or not, but he's active and visible at the masquerade ball. He's definitely a bad guy, at least in Jack's mind, and might even be the real manager of the Overlook, the devil himself.