John Buchan, 1st Baron Tweedsmuir

26 August 1875 – 11 February 1940 was a Scottish novelist, historian and Unionist politician who served as Governor General of Canada, the 15th since Canadian Confederation.

John Buchan wrote The Thirty-Nine Steps while he was ill in bed with a duodenal ulcer, an illness which remained with him all his life. The novel was his first "shocker", as he called it — a story combining personal and political dramas.

The novel marked a turning point in Buchan's literary career and introduced his famous adventuring hero, Richard Hannay. He described a "shocker" as an adventure where the events in the story are unlikely and the reader is only just able to believe that they really happened. (Excerpt from Wikipedia)