Piet Mondrian was a Dutch painter known for his role in the development of abstract art. He is best recognized for his distinctive style, which features a grid of vertical and horizontal lines filled with primary colors like red, blue, and yellow, along with black and white. This approach aimed to express a sense of order and harmony in art. Mondrian was a key figure in the De Stijl movement, which emphasized simplicity and abstraction. His work sought to reflect the underlying structure of reality, moving away from representational art. His influence can be seen in various fields, including design and architecture.