Sir William Henry Bragg (1862-1942), a British physicist and one of the founders of modern solid state physics. He studied mathematics at Trinity College, Cambridge in his early years and served as Professor at the University of Adelaide, Australia, the University of Leeds and the University of London, UK, he became President of the Royal Society in 1940. Due to his pioneering contributions to the use of X-ray diffraction to study the atomic and molecular structure of crystals, he shared it with his son W.L. Bragg. The Nobel Prize in Physics in 1915. It is unique in history that two generations of father and son won the same Nobel Prize. At the same time, he was also an outstanding social activist and was a British public figure in the 1920s and 1930s. **A man of the hour in affairs.