Nic Fizelle was a sophisticated Frenchman who taught me French initially and then history at the London Oratory School, which in those days was a primitive place. It had been used as a prisoner of war camp and still had bars at the windows. Many of the staff were poorly equipped and piety seemed to be the main qualification for being a teacher there.

So it was extraordinary to find this exceptional, intellectual man, who was independent and not part of the teaching establishment, in their midst. He was quite slight and somewhat deaf, and he wore the kind of spectacles that act as hearing aids. He was mercilessly mocked by the pupils, who were very unruly and rather savagely disciplined by the other teachers.

Nic sort of imposed order, but he wasn’t very interested in discipline, and boys would shout and throw bits of chalk around in lessons. He was interested in engaging his pupils and having a proper intellectual exchange. He treated them like adults who would be interested in the facts of either the French language or history. It was he who first introduced me to history as a question of cause and effect, instead of an unrelenting recitation of facts which you had to learn to pass an examination.

He taught me to “look outside the box”, as they say now, to question history, never to assume that things happened because they were inevitable.

The essays I wrote for him were pretty good because he taught me so well.

His methods were alien to many, but those of us who responded were remarkably well educated as a result.

He talked fearlessly to 13 and 14-year-olds about Marx and hardcore political exposition of the way history had been shaped. He was very interesting in lots of ways.

We would discuss all kinds of things and eventually - probably rather dangerously at the time - he invited me to his house. We would have a bottle of wine and he introduced me to French music, particularly Debussy and Ravel, and the poems of Baudelaire and the whole world of French culture. He’d been in the Resistance in France during the war and won various medals. But the thing that struck me most was that on VE day, because of the stress, all his hair fell out and then grew back again half white and half black.

He lived in a small house off the King’s Road in Chelsea, which was full of beautiful objects of an exquisiteness I hadn’t encountered before. When he gave me an edition of Baudelaire’s Les Fleurs du Mal, there was no ulterior motive; he was just delighted to find somebody who was interested in the things that interested him.

I would have said he was gay, but he was not practising because he was a strong and sophisticated Catholic. He became a confidant. My parents had separated and I was brought up by my mother and grandmothers, so he filled a gap because there was no man in my life at that time.

Nic was like a godfather to me, or a wonderful older brother, or a young uncle. We kept in touch after I left school and went to the opera together.

When I started working in the theatre - in the box office at the Old Vic - I’d get him tickets for things and we’d go and analyse them carefully afterwards. He stayed on teaching at the Oratory until he died quite young in the early 1970s. I was still at drama school, so he never saw me on stage Actor, director and writer Simon Callow’s film credits include A Room with a View, Amadeus and Four Weddings and a Funeral. The second volume of his biography of Orson Welles, Orson Welles: Hello Americans was published in paperback on May 24. He was talking to Pamela Coleman.