Pieter Cornelis "Piet" Mondriaan, after 1906 Mondrian was a Dutch painter.
He was an important contributor to the De Stijl art movement and group, which was founded by Theo van Doesburg. He evolved a non-representational form which he termed Neo-Plasticism. This consisted of white ground, upon which was painted a grid of vertical and horizontal black lines and the three primary colors.
Between his 1905 painting, The River Amstel, and his 1907 Amaryllis, Mondrian changed the spelling of his signature from Mondriaan to Mondrian.