 Allingham makes various references to Campion's aristocratic background, and hints at a connection to royalty in several asides.A study of the books suggests his father was a viscount and was already dead at the start of the series.Campion's mother is mentioned several times and writes a letter in "The Fashion in Shrouds", and Campion borrows a car from his older brother (apparently the current holder of the title) in "Mystery Mile", but neither of them appears in person.