Given his father's military career, his childhood was peripatetic. His parents were constantly on the move between postings in India and Burma, with frequent trips home to Britain. His father was hopeless with money, as was Duncan. Hence the great significance of the idea of home in his subsequent life and work, after he settled down for the first time at the age of 17 in the uncomfortable position of a poor relation in the bustling household of his aunt, Lady Stephen, which he memorably described as "that vast Caravanserai that was 69 Lancaster Gate".
Surrounded by garrulous Strachey cousins he found his own peace and quiet in the world of museums and galleries, a quality he shared with Vanessa Bell, with whom he lived for almost half a century. They protected one another from the intrusions of over-literary relations, and recognised an equally intense commitment to the less consciously intellectual routine of the studio.
It was never going to be an easy relationship. As he noted in a 1918 diary: "I was hurt slightly by her saying she got no more from me than a brotherly affection ... I am so uncertain of my real feeling to V that I am utterly unable to feign more than I feel when called upon to feel so much ... the only thing lacking is my feeling to her in passion ... All I feel I can do is to build slowly for her a completely strong affection on which she can lean her weary self."
Certainly there were emotional costs for them both, but these did not I think outweigh the gains of deep, enduring love and mutual respect. In 1930 he asked himself, in the throes of an unhappy love-affair, why Vanessa "does not believe that I love her as much as ever I did? When she is unhappy I am unhappy too ...I want too much I suppose ... As I am made as I am I must do the best with myself and ... with others."
After reading this book, it is not possible to regard Vanessa Bell simply as a kind of injured innocent, as is currently fashionable in American feminist martyrology. Their long relationship possesses its own integrity, and enabled both of them to sustain major creative careers on their own terms, as they chose, within a society that sadly remains strongly moralistic and homophobic.
Here as elsewhere Frances Spalding has contributed substantially to the beginnings of a serious reconsideration of their work. It has previously been absurdly neglected or belittled, most regrettably obscuring their unique contribution to early modernist European art.
Spalding guides us deftly through a long life which contained at least as many disappointments as triumphs. Through it all Duncan Grant remained an overwhelmingly loveable man - loyal, trustworthy, generous, kind, funny, sexy, modest and entirely unassuming. He genuinely liked women, and was never entirely happy in the somewhat brittle, men-only world inhabited by so many early 20th-century British homosexuals. Always his own man, he was never a slave to fashion, never doctrinaire. The only past he dwelt upon was that of painting.
He appears here as a remarkable modern figure. That he was also perhaps the greatest British painter since Gainsborough, with whom his art has many affinities, is another good reason for reading this shrewd and thoughtful book.
It is thus particularly regrettable that its publishers have evidently taken so little trouble with the quality of most of the photographic illustrations.