David Dawson: life after Lucian Freud

At 52, David Dawson is full of the energy of a man who feels he is embarking on a new life. It will begin for him, in part, when a show of his paintings opens at Marlborough Fine Art in London this month – his first solo exhibition as an artist. It would be fair to say that Dawson's has been a long and unique apprenticeship. For 20 years up until the death of Lucian Freud in July 2011 he was cast in the role of the painter's trusted friend, confidante, advisor and most frequent subject and muse.

Having come to London and the Royal College of Art from his home in Wales to paint in his 20s, Dawson instead found himself the essential daily assistant to the great British artist in his final spectacular burst of energy. It was a late period that culminated in Freud's last portrait of Dawson, naked, with his dog, Eli, a whippet: a picture called Portrait of the Hound.

Freud worked on that large canvas for nearly three years. Dawson and Eli lay obediently on a mattress for him most mornings between about 8am and 12.30pm. By the very end, at 88, Freud only had the energy to paint for half an hour or so but he laboured to have the picture complete for his long-planned retrospective at the National Portrait Gallery, which eventually happened posthumously. That painting and that show also marked the closure of Dawson's former life.

He meets me at the porch door of his semi-detached house in a cul-de-sac in northwest London, with Eli impatient at his heels. It was from this house that Dawson set off early each morning down to Kensington to set up Freud's studio for him, and to it that he returned each afternoon, 365 days a year, to think, in the hours before dinner, also usually taken with Freud, about what he might paint himself. Confronting his own canvases was, he recalls, in the face of each morning's evidence of Freud's unremitting concentration and genius, a somewhat daunting task.

"That was the hard thing," Dawson says with his affable smile. "I would come back here and think: 'Fucking hell, what hope have I got?'"

An inspired, instinctive photographer – his snatched pictures from Freud's studio, of the painter and models that included Kate Moss, David Hockney and the Queen, form an oeuvre in themselves – his first thought as an afternoon artist was to paint from photographs that he took on his daily commute, of odd early-morning street scenes in Kensal Rise and Holland Park. He found, however, that he was always "painting the flatness of the photograph as much as anything", which frustrated him. Eventually he took, instead, to painting over and again the view from his upstairs studio window – the semis opposite, and the cherry tree outside – on large canvases that allowed him to stand in one spot and just about reach their four corners.

It is these intense, obsessive paintings that Dawson shows me first in his living room. The paintings of the street outside are stacked against the wall of his dining room, by the patio doors, ready for the Marlborough show, where they will share space with Dawson's paintings from mid-Wales (where he grew up, and now owns a farmhouse) and from New York, looking out over Central Park (where he stays often with Freud's old friend John Richardson, Picasso's biographer). The paintings of each place have a singular, vibrant life; though based on concentrated looking, some seem internal landscapes as much as anything – examinations of the sometimes wild and whirling territory of memory and loss.

Dawson has, he says, been pursuing these three visions of his life with a compulsive full-time energy in the two years since Freud died. He did not share much of his work with Freud while he was alive, but the manner of the paintings and overpaintings suggests a communion all the same. Freud liked the long hours of the artist's struggle to be present in the finished painting. The work has been, in part, a mourning process, Dawson suggests, in front of paintings layered with emotional effort: "Grief is strong stuff," he says. "It hits you without much warning. The work is the best practical response to it I think. It's at times like these, anyway, you are grateful that you are a painter."

Talking to Dawson, who has an easy, almost boyish manner, with an edge of sharp self-knowledge, you begin to see what Freud, never much interested in long-term arrangements, saw in him; what made him the chosen companion of the artist's last years. Freud described him, to others, as a "deeply honourable man". Dawson, above all, understood the painter's total single-mindedness, since he had known a version of it himself.

Dawson was brought up on his parents's hill farm near Welshpool; his father hoped to pass the farm on to him, but he only ever wanted to paint that landscape, not work it, and when he left the farm had to be sold. He didn't come to London until he was 23, but it was with a clear vision of how he wanted to spend his life, in front of a canvas. After art school in Chelsea he shared a studio with the young Tracey Emin for a while – a pairing of extroversion and introversion it is quite hard to imagine, though they remain friends. Dawson's plan was to go to New York to work, but a part-time job with Freud's gallerist led him eventually to the studio in which he found his vocation.

It was love at first sight. "I had all these plans," Dawson recalls, "but straight away it was: hang on a minute, it isn't going to get any better in New York. I walked into Lucian's studio at the time he was painting Leigh Bowery in a room not much bigger than this." One of Freud's paintings of Bowery subsequently sold at auction for $9.3m, then a record for a living artist. At the time Dawson first visited the painter was 69, and the prices for his work had not yet begun to reach those heights. "It was," Dawson says, "just jaw-dropping power. As an art student I was looking at American painters mostly; I was aware of Lucian of course, but when I went to his studio and saw what he was doing, I couldn't believe it."

They got on very well immediately, and Dawson defined a place for himself. "I could see, at nearly 70, that Lucian was incredibly ambitious still for his work," he says. "I felt he was really going to push things. And, oddly, I knew what I could do to help him. Which was: clear space for him to paint. It all just grew out of that first meeting. It felt right on both sides."

For a long while Dawson had the original zero-hours contract. "Lucian would just phone me every morning and ask me to come over. And then each afternoon it would be just like, 'See you.' We went on like that for a long while." Eventually the friendship became the whole shape of Dawson's life; he has no dependants and has always lived alone in this house, devoting himself to Freud's art.

"It was only when I started sitting for him that I really watched him work," he says. "Otherwise he would keep his studio door closed. Now and again he would call me in for 10 minutes." Dawson sat for seven portraits in all, after Freud announced he was "ready to paint him", to which he replied, "Do you want me to take my clothes off?" The process was endlessly fascinating to both men. "He wouldn't have the canvas facing away from his subject," Dawson says, "he would be side on mostly, so you could see him touch his brush to the canvas. His touch was very light and precise every time. He never did anything lazily. And he could keep it up for hours once he got going. I mean I can paint for two hours fully concentrating and then I am exhausted. It was the opposite with Lucian almost, the painting completely energised him. He would have to go out at the end of it because the adrenaline was still up. It was like being a stage actor or something, every night, I imagine."

The pair of them would take breakfast most days at Sally Clarke's restaurant on Kensington Church Street, and dinner was often at the Ivy or the Wolseley on Piccadilly. Freud hated being stared at or photographed. Fellow diners with surreptitious camera phones were likely to receive a volley of bread rolls or carefully aimed olives. It took a long while, even in the privacy of the studio, for Dawson to feel that he could take a picture, though when he did so eventually, he produced perhaps his most indelible work: portraits of the artist as an old, ragingly creative man.

"I never kept a diary and didn't want to," he says. "Early on, I thought I am not going to have this great friendship and then run home and write about it. It didn't feel right. But because I was so fascinated with what was going on in the studio I would have a little camera and take a picture or two. It started really when I was taking a picture of David Hockney in the studio, who had been sitting for Lucian, and Lucian walked in." Freud was wearing a painting apron, "looking like a butcher". He liked that portrait a great deal and afterwards Dawson was free to take pretty much what he wanted, though he didn't push it. One exception was when Freud was painting his diminutive, brutal portrait of the Queen.

"For that I would go to St James's Palace, set up the easel and paints, and wait for the Queen to arrive. And then I would leave. One day I asked the Queen would she mind if I took a photograph. She said, 'I think it might be a little bit of history.' I literally took four or five photos. The first one was a bit shaky, but the others dead on…"

Does he miss all that surreality?

"No, I still get invited to a lot of wonderful things. People have shown me huge kindness," he says.

One thing that hasn't changed is that Dawson still makes a daily commute down to Freud's studio and house in Kensington, which was the painter's bequest to him. Freud used to worry occasionally to friends that he was too demanding of Dawson, that he kept him from his own work. It is a nice reciprocal gesture, you might say, that he has now left his former assistant the means to pursue his own painting career without distraction, just as Dawson for so long enabled him to do. "I am very grateful to him for that," Dawson says, "to paint full time. It's a wonderful thing."

Sometimes on his visits to the old studio he does small paintings. "It's quiet and it's private, and full of good, powerful presence."

Dawson plans to move into the house once he has done a few repairs – "The roof leaks, the wiring needs doing, all that. I will turn it around a little bit, but it will stay in large part intact. I have my own history there, of course. I was there every day for 20 years and it is full of that time."

He is, he says, on friendly terms with Freud's complicated and extended family, which involves 14 acknowledged children, and others. "I think they are working really well with each other. I think they have surprised themselves in a way," he says.

Do they come by the house?

"No. It doesn't really work like that…"

I wonder, with some of this in mind, whether he was shocked or amused over the years by Freud's famously wild attitude to money, the millions lost in gambling on horses.

"Both," he says. "His real buzz had been to win or lose everything when he was a younger man. Then, when he was skint and owing large amounts and people were chasing him for debts, he would really get painting. After a few years the paintings got very valuable. He had too much money then to get rid of. People couldn't take his bets because they would have been too big, so he had to hold on to it."

Dawson draws from that gambler's spirit the chief lesson that he also learnt from Freud the painter, of putting everything on the line all the time: "If you took one thing it was that painting is about risk, and total commitment to what you are going to do. And the belief that if it is crap, recognise it and start again."

That, and the need to keep at it. In his second life Dawson has paintings waiting to be finished in New York; he has 10 canvases on the go in Wales, up on scaffolding poles outdoors at his farm in the next valley to where he grew up; he paints every day, wherever he is, always in the spirit of his mentor. "You have to move it forward a bit every day," he says, "Lucian was a great believer in that."

David Dawson's work is at Marlborough Fine Art, 6 Albemarle Street, London W1, from 11 September to 5 October (marlboroughfineart.com)