I've talked in the past about the difficulty of working out Captain Nemo's age.Indeed, it wasn't just his age that was allegedly altered by his editors. Apparently, if it had been down to Jules Verne, then Captain nemo would have been Polish and not Indian!
Originally, Nemo was said to be of Polish extraction and bitter about his treatment at the hands of the Russians. At the time of publication, however, the relationship between France and Russia needed to be cordial and so Verne was persuaded to change Nemo's nationality! Presumeably, relations between France and Britain weren't so cosy. So Nemo became the son of an Indian Rajah.
Looking at different translations of Verne's work has been fascinating too. Here's a standard British take on why Prince Dakkar (as Nemo was known as a boy) was sent to England: