Niccolò "Nico" di Angelo is a fourteen-year-old Italian-born Greek demigod, the son of Hades and the late Maria di Angelo. He is a main character in the Percy Jackson and the Olympians, The Heroes of Olympus, and The Trials of Apollo series of books, and the protagonist of The Sun and the Star: A Nico di Angelo Adventure. Nico is the younger brother of the late Bianca di Angelo and the paternal half-brother of Hazel Levesque. He is known in the Underworld as the "Ghost King" after taking the title from Minos in The Battle of the Labyrinth. He is an openly gay boy, having been outed in The House of Hades by Cupid who forced him to admit that he had a crush on Percy Jackson. Nico is the boyfriend of Will Solace.