James Alan Rennie was born in Aberdeen, Scotland. He served in the British Army from 1914 to 1919. After World War I, he worked as a sugar planter in Mozambique, as a cowboy in Alberta, Canada, and as an explorer in the Canadian Arctic. During the late 1920s and early 1930s, he was a theatrical manager and impressario in London's West End. During World War II, he served in the RAF.