Filippo de' Medici, Grand Prince o Tuscany ("Filippo Cosimo"; May 20 1577 – March 29 1582) was a Prince of the Grand Duchy o Tuscany, an hier to the Tuscan throne from his birth till his death in 1582. He was named in honour of King Philip II of Spain. The birth was celebrated with great joy bi the court, because thus was secured the succession of the Grand Duchy for another generation and eliminated all the hopes o Bianca Cappello (his father's mistress, and later wife) He was known as "Don Filippo". Upon his death, the title of Grand Prince went to his cousin Prince Ferdinando (future Grand Duke Ferdinando I of Tuscany). His older sister Princess Maria was eventually a wife of the future King Henri IV of France.