Douglas Quadling, an outstanding mathematician and school teacher, was one of the four inspirational drivers behind the School Mathematics Project (SMP) in the 1960s and 70s. The School Mathematics Project, which radically changed the course of mathematics teaching in Britain and more widely, had its impetus at a meeting in a Winchester garden in September 1961 involving Douglas Quadling of Marlborough College, Martyn Cundy (1913-2005) of Sherborne School, Tom Jones of Winchester College, and Professor Bryan Thwaites of the University of Southampton. Over the subsequent 12 months, and supported by a research grant from the University of Southampton, eight schools took part in establishing SMP at the University of Southampton. Douglas, a long-time supporter of SMP, died on Wednesday 25 March 2015. His funeral took place at Emmanuel College Cambridge on Thursday 9 April 2015. We remember Douglas for his exceptional contribution to SMP.