About me: Captain Nemo identifies himself as Prince Dakkar, son of the Hindu raja of Bundelkhand, and a descendant of the Muslim Sultan Fateh Ali Khan Tipu of the Kingdom of Mysore, famous for the Anglo-Mysore Wars (1767–1799) and Mysorean rocket technology. After the Indian Rebellion of 1857, in which Dakkar lost both his family and his kingdom, the prince devoted himself to scientific research, ultimately building the Nautilus and cruising the seven seas with a crew of devoted followers. They gather bullion from various shipwrecks in the ocean, most notably from the hulks of the Spanish treasure fleet sunk during the Battle of Vigo Bay. Nemo claims to have no interest in terrestrial affairs but occasionally intervenes to aid people in distress, e.g., by giving salvaged treasure to participants in the Cretan Revolt (1866–1869) against the island's Turkish rulers; by saving (both physically and financially) a Ceylonese or Tamil pearl diver from a shark attack; by rescuing the castaways in Twenty Thousand Leagues Under the Seas; and by covertly protecting another set of castaways in The Mysterious Island.
Like many actual Indian princes of the era, Nemo received a Western education, during which, as he states, he spent his youth touring and studying throughout Europe. In his first meeting with Professor Aronnax and his companions, the three castaways speak to him in French, English, Latin, and German; Nemo later reveals that he is fluent in all of these tongues. Aronnax praises the captain's French, noting that he "expressed himself with perfect ease and without any accent." Relying on his intuition and knowledge of ethnology, the professor concludes that "there's southern blood" in him but can't determine the captain's exact origin. The Nautilus's library, lounge, and art collections reveal that Nemo is intimately acquainted with European culture, also that he's an accomplished performer on the organ.
Nemo dies of unspecified natural causes on board the Nautilus, docked permanently inside Dakkar Grotto on Lincoln Island in the South Pacific. Cyrus Harding, leader of the castaways whom Nemo protected, administered the last rites, then submerged the Nautilus in the grotto's waters. Shortly after, the volcanic island is destroyed when magma reaches the sea water in Dakkar Grotto, creating a massive steam explosion which blows the island and the Nautilus to pieces.