Sergio Leone was an Italian film director, best known for his 'Spaghetti Westerns' such as 'The Good, the Bad and the Ugly' and 'Once Upon a Time in the West'. He was also the director of the gangster epic 'Once Upon a Time in America'. Leone's films are characterized by their epic scope, dark humor, and moral ambiguity. He is considered one of the most influential directors in the history of cinema.