Andrew Graham-Dixon is on a mission. The art historian and critic is determined to share his passion for great paintings with the aim of enthusing new art-lovers. And he has a missionary’s zeal.

Through his television programmes and writing, he encourages us to look beyond the obvious and delve into the backstories behind the world’s great art. And last night he did the same thing as he addressed a packed house at The North Wall arts centre at St Edward’s School, Summertown, to talk, unsurprisingly, about paintings. He also took time out before the show to talk to pupils from ‘Teddies’ and other schools – who were given free tickets to join the event.

“It’s like Desert Island Discs, but with pictures,” he said. “I like looking different pictures and exploring whether, when you know something about them, they become more interesting. You end up looking at them completely differently.”

He gave, as an example, the portrait of John Ruskin by John Everett Millais, in the Ashmolean Museum.

“Once you realise the man who painted it ran off with Ruskin’s wife you look at it in a different light,” he says.

“It’s an encouragement to people to look beyond the label.”

Andrew’s approach to looking at pictures, sculpture and buildings has revolutionised art broadcasting.

“When I first wanted to make a history of art, I was told by someone at the BBC that the way to do it was cover the six most famous painters, from Van Gogh to Monet, then wait a bit and do them all again,” he recalls, in that distinctive cut glass voice.

“But we decided to do art from countries that no one had ever thought of. No one had done anything on Japanese art for 30 years, except Blue Peter. No one had done Scandinavia, Germany, Spain or America either. We set out to change people’s perceptions.”

Andrew is the public face of art history, presenting numerous landmark series for the BBC, including the acclaimed A History of British Art, The Art of Eternity, The Battle for British Art and programmes on Caravaggio, the Mona Lisa and the Renaissance.

His travels have taken him from Italy and France to Spain, Germany, Russia and China.

A lover of Italian culture, in particular, he recently teamed up with chef Giorgio Locatelli to enjoy food and art in Italy Unpacked. He can currently be seen exploring the Queen’s own treasures, and the stories behind them, in Art, Passion and Power: The Story of the Royal Collection.

An important figure in contemporary art, Andrew has judged the prestigious Turner prize and was an early supporter of the Young British Artists (YBAs) – Damien Hirst, Tracey Emin, Gillian Wearing and Rachel Whiteread – putting on one of their first shows.He has written columns on art for the Independent and Sunday Telegraph among others and had books published on medieval painting, sculpture and the works of Michelangelo and Caravaggio.

The talk is part of The North Wall’s series of Inspiring People talks, which aim to educate and inspire. Other speakers include the historian Bettany Hughes and the environmentalist Jonathon Porritt, with half of all tickets offered free to local schools.

For Andrew, returning to Oxford was a homecoming of sorts. The Londoner graduated from Christ Church in 1981. Coming up to study English he was already an art enthusiast, having taken a year out soaking up Renaissance art in Italy, having finished his A Levels by the age of 16.

“I really enjoyed it,” he says. “By the time I got to Oxford, at 17, I was already interested in art.”

He spent time in the Christ Church Picture Gallery and the Ashmolean. “I usually went to the Ashmolean which, in those days hadn’t been renovated,” he says. “It’s a fascinating museum. Last year’s show of Raphael drawings was one of the greatest exhibitions for 20 years.”

He maintains an enduring affection for its collection, presenting an hour-long Culture Show Special for BBC 2 after its multi-million pound makeover.

It is as a globetrotting art-historian that he is best known, however, basking awestruck in the presence of a renaissance masterpiece, gawping at a church fresco or excitedly pointing out hidden details in the corner of the work of an old master.

So which is his favourite destination? There’s no contest. “Italy,” he says, pointing out the ridiculous number of UNESCO World Heritage Sites within its borders. “Every single town has something amazing, because Italy was rich at the right time and poor at the right time. It was rich in the renaissance and baroque and poor at the time other places were pulling down buildings and building railways.”

His favourite programme though, was his trip around Russia.

“It’s such an extraordinary place,” he says. “There’s some wonderful art, but people are not used to seeing it on their TV.”

So does he dabble in art himself?

“There’s a difference between talking about it and doing it, and I don’t feel any conflict in that sense,” he says cheerfully.

“I think making films is an art form in itself and the way we make films is very collaborative. They are proper works of art themselves. Art criticism can also be seen as a form of art – just look at the work of Baudelaire.”

And finally, who’s his favourite artist? “The artist I feel closest to is Caravaggio,” he says. “After all, I spent 10 years raking over history and trying to find out what happened to the poor man!”