James McNeill Whistler (1834–1903) was an American-born painter and etcher who spent most of his career in Europe, especially in London and Paris. He is best known for his portraiture and tonal paintings, including the famous Arrangement in Grey and Black No. 1 (“Whistler’s Mother”). Whistler advocated “art for art’s sake,” emphasizing composition and mood over subject matter, and he was influential in the Aesthetic Movement. He exhibited widely in Europe and the United States and was involved in several notable artistic controversies, including a famous libel case against critic John Ruskin. His work is recognized for subtle color harmonies, delicate brushwork, and innovative approaches to portrait and landscape painting.