Captain Francis Blake and Professor Philip Mortimer are the brainchildren of Edgar P. Jacobs. The comic first appeared in the Belgian cartoon magazine Tintin in 1946. In the Netherlands, the stories were published regularly in Kuifje Weekblad from 1946 and in Pep/Sjors from 1964. The series follows the adventures of the friends Professor Philip Mortimer and Captain Francis Blake, a spy at MI5. Although the comic is named after both characters, Professor Philip Mortimer is the main protagonist. Mortimer is the one who often gets into difficult situations, after which he gets help from his friend Captain Francis Blake. The stories are set from the 1940s to the early 1960s.