Frederick IV, King of Naples (d. 1504)
Frederick (April 19, 1452 – November 9, 1504), sometimes called Frederick IV or Frederick of Aragon, was the last King of Naples from the Neapolitan branch of the House of Trastámara, ruling from 1496 to 1501. He was the second son of Ferdinand I, younger brother of Alfonso II, and uncle of Ferdinand II, his predecessor.
A combination of King Louis XII of France and Frederick's famous cousin King Ferdinand II of Aragon had continued the claim of Louis's predecessor, King Charles VIII of France, to Naples and Sicily. In 1501 they deposed Frederick; Naples initially went to Louis, but by 1504 a falling-out led to Naples' seizure by Ferdinand, after which it remained part of the Spanish possessions until the end of the War of the Spanish Succession.