31 March 1890   Sir William Henry Bragg and Sir William Lawrence Bragg.

William Lawrence Bragg was born in Adelaide on 31 March 1890. 

William Henry Bragg arrived in South Australia in 1886 to take up the post of Professor of Pure and Applied Mathematics at the University of Adelaide. He was also to give instruction in physics although he was not trained in the subject which was to become a major part of his life in later years.

On 1 June 1889 he married Charles Todd's daughter, Gwendoline. William Lawrence was the first born of his three children. In 1895 Ernest Rutherford visited Adelaide and he and Bragg became firm friends. The following year Bragg learned of W.K. Rontgen's discovery of X-rays. Excited by this discovery he, with his able assistant, A.L. Rogers, set about producing a new radiation.

William Lawrence Bragg was educated at St Peter's College and the University of Adelaide. He attended Trinity College, Cambridge and after graduating became a fellow and lecturer in natural science. By this time his father was back in England and the two worked together on X-rays. They were both awarded the Nobel Prize for Physics in 1915. During World War I both men worked on different problems for the war effort. Bragg senior was appointed to the Chair of Physics at University College, London. He was knighted in 1920 and died in London on 12 March 1942.

In 1938 William Lawrence succeeded Rutherford as Cavendish Professor of Experimental Physics at Cambridge. He also received many honours in his career and was knighted in 1941. He died on 1 July 1971.

Bede Nairn, Geoffrey Serle (eds), Australian Dictionary of Biography, Volume 7, pp. 387-389.