Career
He served as a staff officer of the British Ministry of Defence with the military rank of Brigadier and was awarded the Order of the British Empire in 1955 in acknowledgment of services to Great Britain. Holmes was also a Freemason. In 1956 he was elected vice-president of the World Esperanto Association, a post he retained until 1964.
After the death of President Giorgio Canuto in 1960, Holmes was acting president until 1962, when Professor
Hideo Yagi was elected to succeed Professor Canuto. After Professor Yagi"s death in 1964, Holmes again was briefly acting president
At the 49th World Esperanto Congress, in recognition of his tireless labour and meritorious service to the Association, he was unanimously elected as honorary president of the UEA, a position he occupied for a decade. In 1974, because of changes to the UEA Steering Committee (Estraro), he resigned the honorary presidency.
Harry Holmes"s last work, Londono Vokas ("London Calling"), published in 1981, related the 75-year history of the London Esperanto Club.