It's big, it's red and it's back. Red Nose Night will dominate BBC1 tonight. Tony Robinson, who has long had a hand in Red Nose proceedings, talks to Will Marlow about events past and present.

Tony Robinson has been involved with Comic Relief right from the beginning. As the charity celebrates its 20th anniversary this year, and its biennial Red Nose Day gets its tenth outing today, Blackadder star Tony, best-known for his portrayal of Baldrick, is participating once again.

Tony has used his comic talents to entertain and elicit cash from viewers on many Red Nose Nights.

He has also visited Comic Relief projects in Malawi, Uganda and the UK to show viewers how their money is being used.

''It's been an enormous learning curve for me and a great privilege,'' he says. ''I think it's very easy to be flattered as someone on the telly - 'Oh it's wonderful that you do all this, blah blah blah' - but actually I think all of us involved have taken away from Comic Relief far more than we've put into it.''

The 58-year-old, who has a son and a daughter, was there in 1985 when the idea for Comic Relief formed in the head of writer Richard Curtis.

Blackadder writer Richard had invited cast members from the show to his house in Oxfordshire to watch Live Aid while they were filming the second series.

Tony says: ''It was a gloriously sunny day and he'd put a little telly on a long lead out into the garden. Tim McInnerny and Miranda Richardson and I were playing frisbee in the garden all afternoon with my little daughter.

''We were all incredibly moved by the images from Live Aid, and as much as that we were moved by the fact these musicians had been able to mobilise so many people.''

When Blackadder filming finished, Richard headed out to Sudan to work with a charity.

While he was handing out rice to starving people, someone suggested he should try something similar to Live Aid with his comedian friends.

A one-man show with Rowan Atkinson at the London Palladium followed, as did Cliff Richard's No 1 single Living Doll with cult comic faves The Young Ones.

It wasn't until 1988 that the first Red Nose Day was held, with an evening of comic entertainment.

''We did Blackadder - The Cavalier Years for it,'' says Tony. ''It was a 20-minute Roundheads and Cavaliers Blackadder. You never know at the time how big these things are going to get, do you?

''I did it because I thought the enterprise was important, but I had no idea how it would take off. We've raised in excess of £350m now and at the first one I remember we were saying, 'Do you think we'll reach seven figures?'.''

Two decades later and Tony is reunited with Blackadder colleagues Rowan Atkinson and Richard Curtis once more, playing Batman sidekick Robin in a Curtis-penned Comic Relief sketch called Spiderplant Man.

''When you've got little legs, tights get very wrinkly, very quickly. I spent the whole day holding on to the top of the tights and jumping up and down. Probably no super-hero has ever admitted that before - I think that probably is the big scoop of this interview,'' he laughs.

The sketch will jostle for the title of Most Memorable Comic Relief Moment 2005 alongside the much-talked about Little Britain sketches featuring Sir Elton John, George Michael and Robbie Williams and the final of this year's Comic Relief Does Fame Academy.

As the 20 poorest countries in the world are all in Africa, Comic Relief is just as important now as it was 20 years ago. Two thirds of the £350m raised has gone to help countries on the continent, while the other third has gone to UK projects.

''What I'm most proud of is the educational side of Comic Relief,'' says Tony. ''We now have a generation of young people who understand why it's so important to drop the debt, and why it's important there should be fair-trade rules for the developing world.

''And if people get involved with the kind of work that Comic Relief does, then the politicians can't turn their backs on it. If you've got a lot of angry people out there saying, 'You've got to do something about this', that's worth ten times as much.''