Henry was commissioned into The Royal Field Artillery and served his country throughout the First World War, spending some time as a Captain and Adjutant in the Northumberland Artillery, before being promoted Major.
After retirement he joined the well-known Ipswich printing company of Norman Adlard & Co. Ltd. and became its Chairman in 1925. He also held directorships in Hadden Best & Co. Ltd. and Dindings Rubber Estates Ltd.
Major Barnes was a former member of Ipswich Town Council and had been a member of the old Board of Guardians and a governor of the Northgate Schools. A Freemason, he was a Past Master of the British Union 114 and the Gippeswik 4254 lodges. One of his main hobbies was the cultivation of Sweet Peas and his exhibits at the Woodbridge Flower Shows won him the cup for the class many years in succession. Other hobbies included the breeding of Airedales and poultry.
In March 1905 he had married Louisa Gibson Blaikie (1877-1960) #10562 who had been born in Kussowlie in the Punjab to Dr Walter Biggar Blaikie (1847-1928) #10563, an Edinburgh educated lawyer and civil engineer who in the 1870s was in India building a palace, a post office, a church, a hospital and a gaol. Walter became a distinguished printer widely known for his special deep purple end papers known as Blaikie endpapers as well as being an astronomer and an expert on Bonnie Prince Charlie.
Major Barnes and Louisa made their home at Stonecroft in Stone Lodge Lane, Ipswich where they lived until he died in 1946 and she followed in 1960.