Writing as: John W. Jennison, John Theydon
According to The Encyclopedia of Science Fiction: "UK author, one of several who became active as mass-producers of genre fiction for UK paperback houses and who remained reticent about personal details during their careers. From about 1945 to the year in which it is thought he may have died, Jennison seems to have written over 100 novels under at least forty pseudonyms, mostly thrillers and Westerns; he began to publish routine but occasionally engaging sf with two novels as Edgar Rees Kennedy, Conquerors of Venus (1951) and The Mystery Planet (1952). Working for Curtis Warren, he then published: under the House Name Neil Charles, Para-Robot (1952); under the Gill Hunt name, Station 7 (1952) and Zero Field (1952); and under the King Lang name, Spaceline (1952)."