Answer:The leader of the Fauvist movement and considered the oldest founder of 20th-century painting is **Henri Matisse**. While the Fauvist movement was a collective effort, Matisse's bold use of color and expressive brushstrokes were highly influential and helped define the movement's aesthetic. He was also a key figure in the development of modern art, paving the way for later movements like Expressionism and Abstract Expressionism.
Answer:Henri Matisse is the answer