 At his death, he was Canon Precentor of Chichester Cathedral and Provost of Lancing College, and had been an Assistant Bishop of Chichester since 1930; he died on 9 March 1937 in Chichester, his son having predeceased him during the First World War.A fund initiated after his death yielded enough contributions to provide a memorial, which can be seen at St Cuthman Whitehawk in Brighton.Southwell was a very prominent Freemason, initiated in the Apollo University Lodge, Oxford, in 1880.