The story of the creative relationship between the Dutch artist Piet Mondrian (18721944) and the British artist Ben Nicholson (18941982) is largely untold, yet during the 1930s they were leading forces of avant-garde art in Europe and their work was profoundly connected. This book accompanies an exhibition at the Courtauld Gallery, London, that will be the first to offer a comprehensive account of the parallel artistic paths charted by Mondrian and Nicholson during this remarkable decade. It will bring together an extraordinary group of paintings and reliefs to show how each artist was driven by a profound belief in the potential of abstract art to attain the highest aesthetic and spiritual power.