I wonder if David Hockney has painted Christopher Sykes? It would be easy enough to imagine the result if so. The jacket photo on this second volume of Sykes’s life of Hockney – like the first, labelled ‘the’ biography – shows the author as full-faced and rubicund, a look that lends itself to his subject’s cartoony line and florid palette. As to Sykes’s portrait of Hockney, it is as colourful, though less stylish.

Given Hockney’s addiction to style, this might have been a good thing. Some artists are blessed with facility, others cursed by it. Picasso, Hockney’s hero, falls into the first category: he could do anything, easily and as it hadn’t been done before. The book opens with a Picasso epigram – ‘I never do a painting as a work of art, all of them are researches’ – and the Spaniard reappears throughout this book as the chief source of Hockney’s inspiration.

At the beginning of this volume, which covers 1975 to more or less now, we find the forty-year-old artist at work on Self-Portrait with Blue Guitar, a painting that nods, via an earlier etching, to Picasso’s The Old Guitarist. Hockney’s self-portrait, Sykes tells us, further explores ‘the Cubist influence of