He was also a noted philatelist who was a specialist in the stamps and postal history of Great Britain.
In 1928, Dendy Marshall was awarded the Crawford Medal by the Royal Philatelic Society London for his work The British Post Office from its Beginnings to the End of 1925.
[3] Dendy Marshall was a member of the Royal Aeronautical Society and the Institution of Locomotive Engineers.
[4] He was educated at Hurstpierpoint and Trinity College, Cambridge,[2] and trained as a barrister but never practised.
[2][5] His collection of railway documents and memorabilia was auctioned at Sotheby's on 13 November that same year.