I got this from Wikipedia: I didn't know only 3 of the actors in the original movies have had parts in DM.
Also Dominic Minghella didn't write the prequel movies he was brought in to revamp the movie premise and characters. I think I knew that but it was entirely MCs idea that DM should be gruff, monosyllabic and rude.
Martin Clunes originally played a character called "Dr Martin Bamford" in the 2000 film Saving Grace and its two made-for-TV prequels, Doc Martin and Doc Martin and the Legend of the Cloutie, which were made by British Sky Broadcasting (BSkyB).
The prequels show Bamford, a successful obstetrician rather than surgeon, finding out that his wife has been carrying on extramarital affairs behind his back. After confronting her with the news, he escapes London and heads for Cornwall, which he remembers fondly from his youth. Shortly after he arrives, he is involved in the mystery of the "Jellymaker" and, following the departure of the village's resident GP, decides to stay in Port Isaac and fill the gap. In these three films the village is not known as Portwenn.
The original deal was to produce two such television films per year for three years, but Sky Pictures folded after the first two episodes were made, so Clunes' company tried to sell the franchise to ITV. ITV felt the Martin Bamford character should be portrayed as a "townie", out of his depth and uncomfortable in the country. They also wanted something edgier, so Clunes suggested the doctor be very grumpy and socially inept.
The new doctor's surname was to be Ellingham, an anagram of the last name of the new writer, Dominic Minghella, who was brought in to rework the doctor's background and create a new cast of supporting characters.
Along with Clunes, the only actors to appear in both versions of Doc Martin are Tristan Sturrock (danny) and Tony Maudsley.(dave the postman).