Writer and creator Anthony Horowitz based the character of Sam Stewart on his childhood nanny and governess Norah Fitzgerald, who had been a WAAF driver during World War II, and used to tell Horowitz stories of her wartime experiences and exploits.
Looking for a replacement for its successful El inspector Morse (1987) series, ITV solicited ideas and picked Foyle's War (2002) out of 300 submissions.
Detective Chief Superintendent Christopher Foyle was voted as the nation's favorite detective in 2011.
To the considerable mystification and annoyance of Anthony Horowitz (writer) and the cast, Simon Shaps, former Director of Television for ITV, who only stayed in the job for eighteen months, announced in 2007 that he would kill off this well-respected and lucrative series after making one final season of episodes. Horowitz had to abandon several scripts for episodes set in 1944, and jump forwards to episodes covering the end of the war in 1945. However in February 2009 it was announced that this decision had been reversed now Shaps had left his TV executive role, and three more episodes would be filmed. The Russian House (2010), set in peace-time, was the first of these episodes.
In a newspaper article and an interview accompanying the series-one DVD set, Anthony Horowitz explained that he was seeking a name which evoked the early 1940s. He thought of Foyles bookshop in London's Charing Cross Road, once known for its archaic business practices and its owner, Christina Foyle; Christopher was the nearest male name to Christina. After Christina Foyle's death, control of Foyles passed in 1999 to her nephew Christopher. Christopher Foyle made a cameo appearance in the episode "Bad Blood (2006)", although his scene was cut from PBS airings in the US.