Karl Pearson FRS (27 March 1857 – 27 April 1936) established the discipline of mathematical statistics. A sesquicentenary conference was held in London on 23 March 2007, to celebrate the 150th anniversary of his birth.
In 1911 he founded the world's first university statistics department at University College London. He was a proponent of eugenics, and a protege and biographer of Sir Francis Galton. He was also a socialist. Pearson was instrumental in the development of regression and correlation theory. One of his classic data sets (originally collected by Galton) involves the regression of sons' height upon that of their fathers'. Pearson built a 3-dimensional model of this data set (which remains in the care of the Statistical Science Department) to illustrate the ideas. The Pearson product-moment correlation coefficient is named after him, and it was the first important "effect size" to be introduced into statistics.