i have seen in an episode what charles last name actually is. the name appeared in the pilot of the show and never occurred since then. it happened when he met with mrs. pembroke about a job. he told her that his name was haha. i had you going there for a second. well, isn't it obvious that once charles decided to go to school at copeland college that he legally changed his name to just charles. think about it. he was so hip and got all the broads. nobody gets that much t & a by having a last name.