In September 1938 Mondrian moved from Paris to London to escape the threat of a German invasion. There he made Trafalgar Square, the first in a series of paintings titled after locations in cities that gave him refuge during World War II. The small, subtly textured planes of primary colors that seem to vibrate within their black perimeters are smaller and their arrangement more syncopated than in many of the artists earlier canvases: color segments expand across two rectangular fields in the larger black grid, and thickened blocks of black function as both line and plane (at lower right, for example). The date "39-43" inscribed on the original canvas stretcher suggests that Mondrian revisited this painting after his flight to New York in 1940 to escape the escalating war.