Early in this gem of a book, Michael Holroyd points out that it marks the last volume in his "confessions of an elusive biographer", a trilogy that began with his memoir Basil Street Blues and then, in Mosaic, moved sideways to explore two enigmatic women interlaced in the family tapestry.

Here, the links with earlier volumes are all thematic and the elusiveness is hardly the biographer's alone. Life itself, this consummate writer of lives shows us, is slippery and mysterious. The atmosphere of this meditation on life and the attempt to capture it in writing is as dreamlike as the place which ties its various elements together: the magical Villa Cimbrone perched high above Ravello and the Gulf of Salerno, where Lytton Strachey, one of Holroyd's earlier subjects, had a fantasy of replanting Bloomsbury. Holroyd came here at different times with both of the present book's dedicatees, who appear in its pages as fellow searchers after ever-elusive truths.

One seeks confirmation of the hope that the father she wishes for was in fact hers and the son of the second Lord Grimthorpe, the late Victorian banker, art lover, politician and philanderer who had bought and rebuilt the villa in the early 1900s. His ashes lie beneath the stone floor of its temple. His vagrant seed and abandoned loves populate the book's stories.

Holroyd's other dedicatee is an Italian biographer, something of a foil for Holroyd himself. She came to the Villa Cimbrone in search of the spirit of her beloved novelist, Violet Trefusis, who had lived in the house with her mother, Alice Keppel, mistress of the Prince of Wales. Here, Vita Sackville-West had visited the young Violet before the Great War and lived out a chapter in the passionate love affair which fed both their fictions as well as Virginia Woolf's Orlando. Lavish and excessive, Violet was, in fact, Grimthorpe's illegitimate daughter.

But the woman with whose story this "book of secrets" begins is Eve Fairfax, the sometime muse of Auguste Rodin. It was while he was a young researcher at the Victoria and Albert Museum that Holroyd developed a fascination for the bronze bust Rodin had made of Eve. Its lingering air of melancholy haunted. He started to make inquiries.

Eve Fairfax, it transpires, was the fiancee of the second Lord Grimthorpe. It was he who commissioned her bust from Rodin in 1901 and sent her to Paris, complete with chaperone, for sittings. In the event, Eve's amorous friendship with Rodin long outlasted her engagement to Grimthorpe. She sat for Rodin over some eight years. They met in Paris or in London and she became for him a femme inspiratrice, the model for some of his best late work.

He paid her the greatest of compliments: "I regard you as a woman who resembles in expression as well as in form one of the 'faces' of Michelangelo." Grimthorpe, having suddenly abandoned Eve in 1904, never paid for the original commissioned bust.

Left impoverished and single, though with an illegitimate son Holroyd has retrieved from scraps of evidence, Eve lived out her life as something of an aristocratic nomad, moving from one grand house to another, until she died at the ripe age of 107 in 1978. Had he but known, Holroyd could have met her. Instead, he is left to conjure her life from her own thick book of secrets – a burgeoning tome she carried from house to house and in which those she met were asked to write.

Alice Keppel appears here. So, too, does Eve's one-time fiance, Grimthorpe, met again in 1915, two years before his death. He leaves Eve a verse from Swinburne's "Dolores", chilling in its resonance. Its last lines read: "And marriage and death and division/Makes barren our lives…"

Reading this book is a little like walking through a hall of mirrors into the final party of Proust's great opus. The rouged and powerful dowagers loom largest: the ancient Eve Fairfax herself; the corpulent Lady Sackville, who also sat for Rodin; Alice Keppel, barred from royal circles once her Prince of Wales was dead, but ever-idolised by her wild daughter; Violet's older and sadistic lover/mother, the Princess Edmond de Polignac; Violet herself, as she takes on years, rouge, and books. Their children have little idea that these women were once aspiring and amorous coquettes whose adventures subtly echo through their heir's lives and in turn down through subsequent generations.

The terrain where aristocracy and bohemia mingle is one of which Holroyd is a past master. Here, he has given us the distilled essence of biography and a fitting end to what he evokes as the "comedy of life".

Lisa Appignanesi's Mad, Bad and Sad: A History of Women and the Mind Doctors from 1800 to the Present is published by Virago.