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:
"His father sent him, when ten years of age, to Europe, in order that he might receive an education in all respects complete, and in the hopes that by his talents and knowledge he might one day take a leading part in raising his long degraded and heathen country to a level with the nations of Europe."
Enlightened eh? No wonder Prince Dakkar despised the English!
Now read the same piece translated for the American market in 1876 (the centenary year of independence!)
"His father sent him, when ten years old, to Europe, where he received a complete education; and it was the secret intention of the rajah to have his son able some day to engage in equal comabt with those he considered as the oppressors of his country."
The difference in those passages is so telling and such a gift to a writer. As you might have guessed, I'm going with the second translation, it has so many possibilities!