Sergio Leone was an Italian film director, best known for his work in the Spaghetti Western genre. He directed some of the most iconic films of the genre, such as 'A Fistful of Dollars' and 'The Good, the Bad and the Ugly'. Leone was also a major influence on other directors, including Quentin Tarantino. His work is considered to be a major contribution to the Western genre and he is often referred to as the 'father of the Spaghetti Western'.