Dutch architect and urban planner. Van Eesteren was a member of the De Stijl group. In 1923, he collaborated with Theo von Doesburg to create series of architectural models based on planes floating in space with the non-colors white, grey and black, together with the three primaries of red, yellow, and blue. Van Eesteren served as president of CIAM (Congrès internationaux d'architecture moderne) from 1931 to 1947. Among his most famous projects was the Amsterdam Expansion plan (1933), which determined spaces for future industrial and housing development in the city.