While it is a constant throughout history that conflict has inspired and engendered great art, it is a much rarer event for art to impact directly upon the vicissitudes of war. Yet, in the course of the First World War, a collision of naval strategy and the nascent modern art movement, led to some two thousand British ships going to sea as the largest painted modernist "canvases" in the world covered in abstract, clashing, decorative, and geometric...