James Breckenridge emigrated to Kenya in 1921 as a young child, following his widowed mother's marriage to the game warden Arthur Blaney Percival. He had a fraught relationship with Percival, who he describes in his autobiography as a bully. The family lived in Nairobi and Machakos and Breckenridge boarded at the Prince of Wales School. After leaving school he worked on farms, joined the Kakamega gold rush and then worked at Nairobi Airport and Mombasa Docks before joining the Kenya Police on his 20th birthday in 1937.
In 1938 James worked his passage back to the UK on the SS Llanstephan Castle, and joined the army. He passed out from Sandhurst after the outbreak of WW2, and was posted to Kenya to join the King's African Rifles on acount of his knowledge of Kiswahili. He served in Ethiopia and Burma, and was promoted to the rank of Major. After the war he settled in Kenya, on a farm in Uasin Gishu, with his wife Caroline (nee Grierson, later Holmes) whom he had met in London in 1945. Caroline already had a daughter, Victoria, and their son Ewan was born in 1948.
James joined the Kenya Police Reserve near the start of the Mau Mau Emergency, and subsequently volunteered his services to the Provincial Commissioner to assist with rehabilitation work. He described his motivation as wanting to help people who had got themselves involved in a terrible organisation, often under duress. He became a Rehabilitation Officer at the Marigat detention camp in 1952, and the family moved to live there. In 1954 he was promoted to take responsibility for the five camps in Embu District, and moved to Thiba camp. Caroline was also appointed as a Rehabilitation Officer in her own right. In 1956, the family were moved to Athi River, from where Caroline also ran activities at "Mile 37" women's camp near Kajiado. Mau Mau detainees were able to pass up the "pipeline" as they confessed and worked towards rehabilitation, and the Breckenridges' work was largely focused on encouraging detainees to confess and be rehabilitated through training, drama and recreational activities. After four years work in the camps they were transferred to the Jeanes School to run a course for Community Development Assistants. Their final assignment was at Karaba camp from 1958-9, where they were tasked with the final rehabilitation and release of hardcore Mau Mau adherents.
In the run up to independence, James was advised that he was on a "wanted" list by ex Mau Mau leaders, and the family returned to the UK in 1961. Caroline died in 1976, and James remarried in 1979. He died in Dorset in 2010.