Submariner, banker and prolific letter writer Walter Ronald (Ronnie) Eyres was a clever, talented, modest man who hid layers of originality beneath a relatively conventional, gentlemanly exterior.

He went on a scholarship to the Royal Naval College at Dartmouth – following his father, England rugby international and navy boxing champion Captain Wally Eyres – then entered the Navy. Ronnie served on submarines just after the sinking of HMS Affray, in which he lost several friends. It must have been a trial for a sensitive man; but Ronnie did not complain and made lifelong friends in the navy.

He pursued a career in the City, first in stockbroking firms and then for 25 years at J. Henry Schroder Wagg.

Ronnie was not a typical merchant banker, often going against conventional wisdom, but he was greatly respected for his skill and success at managing large funds.

One colleague described him as “one of the great contrarian and independent-minded fund managers of his time.”

He became a mentor to young recruits. One described his principles as: “a) running your winners, not tinkering, and thinking long-term; b) buying the Racing Post; c) breakfast at Le Poulbot.”

Ronnie followed the horses ­assiduously, though he only ever bet small quantities. His greatest triumph came when he won an Evening Standard racing competition with a prize of £20,000.

Colleagues recall Ronnie baffling newly-arrived graduates with references to portfolios as being like “gardens full of different plants.”

This organic thinking revealed his passion for the environment, which blossomed after he ­retired. He focussed on green ­issues in local campaigns around Dartmouth Park and Hampstead Heath, as well as the renovation of Highgate Cemetery. In 1994 he stood as Green Party candidate for Highgate Ward, and polled an impressive 628 votes, beating all three Lib Dem candidates.

Cllr Maya de Souza credits this for paving the way for the Green Party’s success in 2006, when two Greens were elected.

Ronnie’s political concerns were channelled into the writing of letters to the Ham&High, as well as national newspapers, many of which were published.

Ronnie was a fine wordsmith and would have made an excellent journalist.

He was especially proud when Chancellor Jim Callaghan quoted one of his letters: “There have only been two sorts of Chancellor since the war, those who ended in disgrace or those who got out in time.” Callaghan, who had a cutting of the letter in his wallet, announced, “I aim to create a third sort of Chancellor, one who started in disgrace but ended in triumph”.

Perhaps Ronnie found his greatest satisfaction as a committed family man. He was happily married for 45 years to June Sarson, and was devastated by her death.

He was intensely devoted to his children, Annabel, William and Lebby, sharing in their successes (including Annabel reaching the finals in the women’s double sculls at 1992’s Barcelona Olympics). He was a doting grandfather to his six grandchildren.

Ronnie was born on June 19, 1931 and died on November 23, 2013.