Could any of you have predicted Blackadder would still be held in such reverence and affection 40 years on?

There are very few series which continue to be held in such affection by so many people as Blackadder. I think we're all slightly puzzled by that. We can see reasons why that might be the case, but we don't actually know if they are the reasons. You can say it hasn’t dated in the same way as other shows because it's historical, but there are other historical series which haven't stood the test of time. Perhaps it was because of the talent of the people involved, which is true, but we've all done other things which have bombed.

Maybe its longevity is because there were so many people involved in its creation the show was rigorously scrutinised in a way one normally wouldn’t be, due to the enormous time pressure of making television comedy. There is a lot of truth in that. What we can say Blackadder did do is capture the talents of an awful lot of very bright and talented people at exactly the right time in their lives.

Do you learn how Baldrick came to be Baldrick during the documentary?

We talked about him quite a lot, because he had a different number of brain cells in each series, usually less than in the series before. Again, memories of his change differ, which is because Blackadder was always a very collective enterprise. You had Ben [Elton] and Richard [Curtis], who were driving the writing, but nevertheless, all of us contributed little grace notes to the writing and it was shot in a variety of ways.

How did his stupidity change over the course of the series?

In the first series, I think he was much brighter than in the pilot. Then in the second series, he became as stupid as he was in the pilot, in the third series he was even more stupid, and by the fourth series he was brain dead. It was completely arbitrary and loads of people had turned it down. I was living in Bristol and, four days before they were due to make the pilot, there was a thump from the front door. There, by the door, was a script from the BBC.

I phoned up my agent and asked, “What's this?” She replied, “I was meaning to tell you about that. They want you to play this little part in Rowan Atkinson’s new series.” I browsed my way through the script and the part was so small I couldn’t even find it the first time. All my life I had wanted to be involved in what I thought of as Oxbridge comedy, from That Was The Week That Was onwards.

I kind of couldn't believe they had been able to make all these wonderful series without having met me, because they were so clearly written with my sensitivity in mind. It’s like that feeling you have when you hear a piece of music which speaks directly to you. So I had the excitement of being able to play this part and then the disappointment of not filming the pilot, due to a strike at the BBC. I hung around but nothing happened, and I then landed a very nice job at the National Theatre.

Then the team contacted me to say the pilot was going ahead, but my job meant I wasn’t available for filming. I thought the moment had passed, so when I later had a call offering me the role, I thought they were taking the piss. They rang me up and said, “By the way, we've got a series of Blackadder.” I said, “That’s great! Enormous congratulations and give Rowan my love. I’m so pleased for you.” They replied, “It’s good for you, too.” I asked them what they meant and they replied, “We want you to play Baldrick.”

The chemistry in rehearsals must have been unforgettable…

I had a wonderful time during that first week, the week that ended with the pilot not happening. In that rehearsal room I just felt absolutely at home. I felt like I'd found my brothers.

How much have you enjoyed the juxtaposition of playing Baldrick in a new Comic Relief sketch and this documentary exploring his dim and distant past?

What was extraordinary about the Comic Relief sketch was how the quality of Richard’s writing meant I slipped back into the role, like you would slip into your favourite pair of slippers. The reaction was so charming. I had a wonderful week leading up to the sketch and then a couple of wonderful days afterwards, because the press were charming, the public were so supportive, and we raised a lot of money for important charities. I said to my wife that everybody once in their lives ought to have the experience I had in those few days on the National Health Service, because it's so good for your soul. 

Pictured: Blackadder Gets Framed - read more here.

Interview/picture supplied by Gold/UKTV