Charles Emmanuel I (Italian: Carlo Emanuele di Savoia; 12 January 1562 – 26 July 1630), known as the Great and nicknamed Testa di Fuoco (Piedmontese: Testa d'feu; "Hothead", a sobriquet attributed to his aggressive and rash military character), was the Duke of Savoy and ruler of the Savoyard states from 30 August 1580 until his death on 26 July 1630, nearly 50 years later. At the time of his death, he was the longest-reigning Savoyard monarch, a record later surpassed by his great-grandson Victor Amadeus II.
A bold and ambitious ruler, Charles Emmanuel sought to expand Savoyard influence throughout northern Italy during a period marked by the French wars of religion, the Thirty Years' War, and intense rivalry between France and Spain. He led multiple military campaigns – annexing Saluzzo, Trino and Alba but losing Pinerolo and some transalpine territories – and often played European powers against each other in complex diplomatic maneuvers. He was also a patron of the arts and a writer himself.