Piet Mondrian (1872-1944) was a founder of the De Stijl movement which characterised the Modernist aesthetic. Through abstraction, Mondrian believed he could reduce form to its pure fundamental state. Simplified shapes, strict geometry and primary colours create the striking modern works that remain familiar in popular culture to this day. Still influential, Mondrian’s philosophy of design rested on a balance between opposing forces of nature, represented by the horizontal and the vertical in his paintings.