Captain Nemo, also known as Prince Dakkar, was a famous sailor who was one of the main protagonists in the novel Twenty Thousand Leagues Under the Sea. Nemo, one of the best known antiheroes in fiction, is a mysterious figure. The son of an Indian Raja, he was a scientific genius who roams the depths of the sea in his submarine, the Nautilus, which was built in pieces all over the world and shipped to the builder.
Nemo tries to project a stern, controlled confidence, but he is driven by a thirst for vengeance and a hatred of imperialism focused on the British Empire. He was also wracked by remorse over the deaths of his crew members and even by the deaths of enemy sailors.
Nemo's character in the novels is largely seen through the observations of Professor Pierre Aronnax, the narrator of Twenty Thousand Leagues Under the Sea, when Nemo was about forty years of age and described as a reticent man, tall and swarthy in appearance, with a straight nose and wide-set eyes. In The Mysterious Island, the aged Captain Nemo sports a long white beard.
He avoids dry land, except when it's uninhabited, as with Antarctica and desert islands. In keeping with his contempt for the nations of the surface, he used no products that are not marine in nature, be it food, clothing, furnishing, or even tobacco. Little is revealed about his political opinions except an almost maniacal hatred of oppression, with which he identifies all the imperialistic nations of the world. He therefore identifies himself with those oppressed.
Nemo was devoted to his crew and grieves deeply when one is killed in the giant squid attack in the Caribbean Sea, or after a midnight encounter with a surface ship. He showed the same compassion in his treatment of the castaways, and retained a strong attachment to his deceased wife and children. Though short-tempered, he rarely expressed his anger. He was also a man of immense courage, in the forefront of every activity.
An extraordinary engineer, Nemo has designed and built the Nautilus, besides inventing her electric propulsion and navigation systems. He has an exceptional mastery of underwater navigation, taking upon himself the most difficult submarine passages, such as those under the Isthmus of Suez and the Antarctic ice sheet. He has a comprehensive knowledge of marine biology, and it is his respect for Professor Aronnax's expertise in the field which led to his befriending the professor when the latter was cast upon the Nautilus. Further, he is said to have read and annotated all the books he possessed in the Nautilus's vast library.