John Leathes was born on 26 January 1896, the son of Herbert de Mussenden Leathes – a Captain in the 3^rd Battalion, Yorkshire Regiment and Agnes Isabel Leathes (née Stephens). 

He  joined the Royal Navy in 1909 and served in the Battleship HMS VANGUARD from 1913 to 1916. He was appointed to HMS DOLPHIN ‘for Submarine training’ in 1917 and later to HMS LUCIA ‘for Submarine C22 as First Lieutenant’.  He was then promoted to Lieutenant in 1918 and appointed ‘for Submarines E31 as First Lieutenant’. 

December 1919 found him in Hong Kong as First Lieutenant of L3, but, by August 1922, he was back in Britain as Commanding Officer of H50. Commands of L52 and, as a newly-promoted Lieutenant Commander, H44 followed. He returned to the Mediterranean in August 1928 with an appointment to L26 in Command. 

On his return home in 1930 he was appointed to the Submarine Tender HMS ROSS to command HMS M2.

He died when M2 was lost with all hands in the English Channel on 26 January 1932, on John Leathes’ 36th birthday, although the submarine was not listed as officially lost until 29 January.

His estate was left to his wife – Florence Beatrice Leathes (née Taylor) – whom he had married in St Georges, Hanover Square, London in 1922.  He had a son, John Alexander, born in 1928, who also served in the Royal Navy, retiring as a Commander and who died in 2020.

Note also that a 2nd Lieutenant Robert Herbert de Mussenden Leathes, ‘B’ Battery, 62nd Brigade, Royal Field Artillery died on 18th April 1917. He is buried in Section B, Grave 1 in the Bunyans Cemetery, Tilloy les Mofflaines, Pas de Calais, France. There is also a Memorial in the form of a marble plaque in the entrance porch to St. Margaret’s Church, Parish of Herringfleet, Suffolk.