Sir William Henry Bragg was an English physicist, chemist, mathematician, and active sportsman who uniquely shared a Nobel Prize with his son Lawrence Bragg – the 1915 Nobel Prize in Physics: "for their services in the analysis of crystal structure by means of X-rays". The mineral Braggite is named after him and his son. He was knighted in 1920.

Sir William Lawrence Bragg, was an Australian-born British physicist and X-ray crystallographer, discoverer (1912) of Bragg's law of X-ray diffraction, which is basic for the determination of crystal structure. He was joint recipient of the Nobel Prize in Physics in 1915, "For their services in the analysis of crystal structure by means of X-rays"; an important step in the development of X-ray crystallography.