Freud was a great divider. He allowed few of us to see any of the others. The central crossroads in his later life were his painting studio and Clarke’s. Everyone important to him in his final years met there.

He was entrenched in life-study portraiture and he made it provocative. ‘It is the only point of getting up every morning: to paint, to make something good, to make something even better than before, not to give up, to compete, to be ambitious,’ he said.

Lucian had been remarkably fast out of the starting blocks in his teens and early twenties (the Museum of Modern Art in New York had bought a picture in the 1940s), but then there was a very long period when his paintings sold only to a small number of English people and he enjoyed almost no international recognition. In the early days of their relationship Freud was encouraged by Bacon and eventually he followed his more reckless, free-style approach, abandoning his Germanic tightness of line and fine surfaces.

He was often virtually penniless in his early days, spending almost all his money on paint. ‘Until I was fifty I never had a bank account, always lived from hand to mouth. I used to lie awake at night wondering if I’d be able to go on with my paintings or whether the paint would run out.

He was on the threshold of his ‘disturbing’ or ‘hallucinatory’ period, which led Herbert Read, the critic and co-founder of the Institute of Contemporary Arts, to describe him as ‘the Ingres of existentialism’. It was a compliment that Lucian enjoyed, Ingres being one of the painters he most admired.