George Charles Spencer-Churchill was 8th Duke of Marlborough. He married firstly Lady Albertha Frances Anne Hamilton and secondly, Lillian Warren Hammersley, née Price.
JW negotiated with the Duke through the dealer D. C. Thomson in April 1892 to paint his portrait and that of his wife. He made a preparatory study (r. and v.: Study for a proposed portrait of the Duke Marlborough (M.1337)) but unfortunately the Duke died in November 1892 before the commission could be completed. See #04021, #05723, #05758, #08342, #08319.
Burke, E., The Peerage and Baronetage of Great Britain and Ireland, London; Debrett's Illustrated Peerage, 1896.