Marie Neurath (née Reidemeister; 1898–1986) was born in Braunschweig (Germany) and studied at the University of Göttingen. In 1924, just before graduation, she met Otto Neurath (1882–1945) in Vienna and (in March 1925) went to work there as his assistant in what had been a small museum of information about housing. At the start of 1925 this became the Gesellschafts- und Wirtshaftsmuseum in Wien (‘Social and Economic Museum of Vienna’). This was the start of her long activity as the main ‘transformer’ (in English, we would now say designer) working with Neurath in the teams that made graphic displays of social information. The other essential member of the Neurath group, the German artist Gerd Arntz (1901–88), joined in 1928. Marie Reidemeister worked at this museum in Vienna until the brief civil war in Austria in 1934, moving then with Neurath (a prominent Social Democrat) and Arntz (who had allegiances to radical-left groups) to The Hague. In 1935 they began to use the name Isotype in the signature for their work. In 1940, as the German army invaded the Netherlands, Neurath and Reidemeister escaped to England, while Arntz stayed behind in The Hague. In 1941, after release from internment (as ‘enemy aliens’), Marie and Otto Neurath were married, and resumed their work in Oxford, founding the Isotype Institute. After Otto Neurath’s death in 1945, Marie Neurath carried on the work with a small number of English assistants, moving to London in 1948. After her retirement in 1971, she gave much energy to establishing a record of Otto Neurath’s life and work, and editing and translating his writings.