Sir Walter's biggest achievement was his co-discovery of the double helix structure of DNA. Franklin's X-ray diffraction patterns of DNA, captured by Raymond Gosling in May 1952, proved crucial to the discovery of the double helix.
While working at King's College London in 1951, Franklin shared her X-ray diffraction images of DNA with Watson without authorization, who made a critical breakthrough in determining DNA's structure. Franklin's data, along with the theoretical analysis provided by Watson and Francis Crick, led to the publication of their ground-breaking paper in the journal Nature on April 25, 1953.