John Barnaby is a cousin of Tom Barnaby, he is a Detective Chief Inspector, first appearing in The Sword of Guillaume. Portrayed by Neil Dudgeon, the character of John Barnaby will replace his cousin Tom as the chief protagonist in the series. This change became necessary when John Nettles announced his retirement.
Detective Chief Inspector John Barnaby was transferred from Brighton CID to Causton CID after his older cousin, Tom, retired. The character appears in the first full-length episode, Death in the Slow Lane where he is being shown round Midsomer by DS Ben Jones, former sidekick to the other Barnaby. When it is revealed that he has a degree in psychology, he ended up getting some rubbing from Jones. It was only after a rocky start that the two made a formidable team. John is married to Sarah and they don't have any children. Instead they have a dog called Sykes and live in a large country cottage..