The first time I met Peter O'Toole was in 1965. As a junior member of the the Royal Shakespeare, I was invited to a bring-a-bottle party in Hampstead. We were all having a wonderful time when, suddenly, there was a sort of hush that came over the room, everyone looked around and there was this extraordinary looking man who had just come in … with his flaxen hair, his jeans tucked into his high boots, looking every inch a Greek God, and there he was: the great Peter O'Toole.

It was many years later that we did the infamous Caligula together. Why I loved him so much is that he never took anything, especially that film, too seriously. In fact his very first words to John Gielgud on the set were: "Hello, Johnny! What is a knight of the realm doing in a porno movie!?" We all had a good laugh about that.

I do recall one particular night shoot… We were called to the set at four o'clock in the afternoon. As usual, nothing was ready. They'd built a set of Tiberius's grotto, on three acres, and were assembling all of the extras and background. The producers worriedly asked if I would go into Peter's trailer (he was playing Tiberius) and go through the lines with him, which we did few times.

And then he told me the most remarkable story – whether it is true or not I have no idea – about his grave-robbing Etruscan tombs. He said the best way to find Etruscan jewellery and artefacts was to find the drains in the tombs, and very gingerly sift through them with your fingers because, as the bodies decompose, all of the artifacts deposit themselves into the channels. The thought of Peter O'Toole on his hands and knees in an Etruscan catacomb makes for a lovely image.

Watch a (grainy) clip of Tiberius and Caligula here

We spent hours and hours in this trailer. He was smoking … it certainly wasn't tobacco. By the time we got onto the set, 12 hours had passed. We couldn't believe our eyes: the set was covered with people engaging in every sexual perversion in the book. We were totally bemused.

Peter would start off his speech, "Rome was but a city..." then pause, look around, and say to me: "Are they doing the Irish jig over there?" I'd look over and there would be two dwarves and an amputee dancing around some girls splayed out on a giant dildo. This went on quite a few times.

Peter then had to go up to one of the sentries and ask, "Caligula! Do you think this man is drunk?" He would say, "More wine!" and they would force more wine down the poor man's throat. Eventually he'd come back to this drunken sentry and he'd say again to me: "Caligula! do you think this man is drunk?" I would respond, "Yes, my lord, I think this man is drunk!" And Peter said, "Sword!" and I would have to fish out a sword and give it to him. But by this time he was so ripped, he could barely grasp it.

Peter very carefully went up to the sentry and looked under his breastplate, where he was supposed to ram this sword into a concealed rubber bladder that contained blood, wine and chicken gizzards to look like a man's innards. He placed the sword under the plate and snapped it up with such force, it hit the poor man in the face and knocked him out.

But, unfortunately, it didn't pierce the bladder. The goat skin, with all the wine and gizzards literally bounced a few times and the whole set, three or four hundred stunned extras, all gazed on this bouncing beach ball. Peter just looked at me with that evil little twinkle in those iconic blue eyes and shouted: "I think she's dropped her fucking handbag!"

Read the Guardian's obituary of Peter O'Toole