Roald Knutsen, born of Anglo-Norwegian parents, has combined a successful career in advertising and occasional film design with more than fifty years study both in the UK and Japan with traditional Kendo, Iai-jutsu, and So-jutsu, holding high rank in the first two. He has written several books on the historical cultural background of the Martial Arts. He co-authored a study of Japanese spears with his wife, also holding high rank in Kendo.