Greenwood qualified in medicine from UCL in 1904. His work as a medical statistician began in 1910. After a spell in the Royal Army Medical Corps (just failing to become Major Major Greenwood!) he joined the Ministry of Health. He was appointed Professor of Vital Statistics and Epidemiology in 1928 at LSHTM. He was elected FRS in 1928. He was awarded the Guy Medal in Gold of the RSS in 1945, having been its President in 1934.
http://timeline.lshtm.ac.uk/images/1940_greenwood.jpg Photograph.