In April 1970, Robert Lowell moved into All Souls College, Oxford, where he was to spend all of Trinity term as a beneficiary of its visiting fellowship scheme (he was replaced by Philip Larkin the following term). Within days of his arrival he went to a party in London thrown by his publisher, Faber & Faber, and met Caroline Blackwood. They spent the night together in a large corner house in Redcliffe Square, Kensington, with which she had been provided by the Guinness family trustees (her mother was a member of the brewing family). Within two months Lowell told his wife, Elizabeth Hardwick, that he would not be returning to her in New York.

Blackwood was soon pregnant with Lowell’s son. The couple married in 1972 after Lowell had divorced Hardwick. The marriage fared badly: Blackwood was an alcoholic (an illness to which her father’s family were disposed) and she could not cope with the manic episodes that recurred during Lowell’s lifelong bipolar cycle. His indecision about his feelings towards his two wives was chronic. Lowell’s life became a perpetual ‘wobble’ as he separated from Blackwood and was reconciled with her, returned to Hardwick and then left her again.‘I feel’, Lowell told Hardwick, ‘like a man walking on two ever more widely splitting roads at once, as if I were pulled apart and thinning into mist, or rather being torn apart and still preferring that state to making a decision.’ The splitting killed him. In 1977 Lowell left Blackwood with the renewed intention of returning to Hardwick. When the yellow cab taking him from JFK Airport stopped at Hardwick’s building, he was found dead on the back seat, having suffered a heart attack, clutching a portrait of Blackwood painted by her first husband, Lucian Freud.

This anguished marital juddering is the subject of the sonnet sequence entitled The Dolphin, which Lowell published in 1973. It included ‘magnificent poetry’, as Elizabeth Bishop told him, with ‘marvels of image and expression’. These dazzling, transfixing, captivating poems chronicle his desertion of Hardwick and his happiness with Blackwood. By incorporating phrases from Hardwick’s hurt and aggrieved letters into the sonnets, by altering and chopping up her words, by wrenching them from their original context and, moreover, by dedicating the book to Blackwood, he aroused accusations that he had pirated, distorted and betrayed Hardwick’s expressions of feeling. The sonnet ‘Exorcism’, for example, concludes with three snatches from Hardwick’s livid missives:

You can’t carry your talent with you like a suitcase.
Don’t you dare mail us the love your life denies;
Do you really know what you have done?

A dignified and careful letter from Hardwick to Blackwood has its opening sentences hacked off and grafted on to the end of another sonnet:

‘Dear Caroline,
I have told Harriet that you are having a baby
by her father. She knows she will seldom see him;
the physical presence or absence is the thing.’

Early in this imbroglio, Adrienne Rich – a good friend of both Hardwick and Lowell – left her husband, who soon shot himself. She was thus in a sore and reproachful mood when reviewing The Dolphin. It was ‘a cruel and shallow book’, the product of an ‘unproportioned ego’, containing ‘bullshit eloquence’, she wrote in an unforgiving anathema. The inclusion in the poems of extracts from Hardwick’s letters, she maintained, ‘stands as one of the most vindictive and mean-spirited acts in the history of poetry’.

‘Sometimes I think I am the enemy of womankind,’ Lowell told Hardwick. He hurt all three of his wives grievously, but he believed in their greatness as writers, enriched them creatively and improved their sense of self-worth. He gave the first, Jean Stafford, lifelong facial disfigurement after crashing the car they were in while drunk at the wheel, and later broke her nose during a drunken row in New Orleans. He also encouraged her during the writing of her first novel, Boston Adventure, which sold over 400,000 copies following its publication in 1944. The novel that Hardwick wrote after marrying Lowell, The Simple Truth, is a big improvement on its predecessor, and the novel she wrote as a response to The Dolphin after his death, Sleepless Nights, is her best. ‘Everything I know’, she attested, ‘I learned from him.’

Reviewers of the US edition of The Dolphin Letters, which brings together letters exchanged by Lowell, Hardwick and others in their social circle during the last seven years of Lowell’s life, have given the impression that Blackwood was an established writer when Lowell met her. In fact, she was merely a spasmodic contributor to Encounter and the London Magazine (its editor, Alan Ross, had been her lover, as had Robert Silvers, editor of the New York Review of Books). It was Lowell who induced Blackwood to assemble her first book of stories and reportage, For All That I Found There (1973), and fostered her prize-winning first novel, The Stepdaughter (1976). ‘Without you everything seems hollow, boring, unbearable,’ Blackwood wrote to him in 1970.

The ‘circle’ around Hardwick and Lowell mentioned in the subtitle of The Dolphin Letters was American. Elizabeth Bishop, Mary McCarthy and Adrienne Rich feature heavily in the pages; their letters, chosen scrupulously by Saskia Hamilton, are essential to the success of this resourceful, lively and absorbing book. Elizabeth Bishop sends Lowell quotations from Hardy, Hopkins and Henry James about the mendacity as well as the cruelty of mixing fact with fiction. Mary McCarthy admits remorse at publishing her Memories of a Catholic Girlhood. ‘Absolute honesty’ about other people can be ‘too cruel’, McCarthy writes, whereas ‘if you are cruel to yourself, you can make it right’. This comes in response to Hardwick’s reflections on the quandaries that face the memoir writer:

No one makes an enemy without wishing to do so. The need is sometimes very pressing; the relief rather disappointing. No, the troubles are not with relatives, lovers, famous persons seen at a deforming angle. The troubles are all with yourself seen at an angle, yourself defamed.

Lowell’s relations with England are less palpable. There are few letters from Blackwood. There is scant mention of Lowell’s staunch friend Grey Gowrie, who was, with Jonathan Miller, one of the few Englishmen able to understand or manage his bipolar condition. Blackwood’s ogress of a mother, Maureen, Marchioness of Dufferin and Ava, is confined to a footnote. Natasha and Stephen Spender, Iris Murdoch and John Bayley flit past like will-o’-the-wisps. Al Alvarez is a ‘strange little shark’ and Quintin Hogg slams doors and ‘snortles like a seal’ (he had once been Lord Privy Seal).

A genteel brand of American cultural supremacism pervades the writings of the ‘circle’. Hardwick’s resentment of the English influences on Lowell at times makes her sound as Anglophobic as Edmund Wilson. She upbraids her ex-husband as a renegade and a deserter of his homeland. ‘You are a great American writer,’ she tells him, ‘the most American of souls.’ In a distraught outburst she reviles Blackwood and Gowrie for ‘their destruction of the dear Yankee genius they will never understand’. There are dollops of Uncle Sam puritanism. Hardwick characterises Blackwood’s milieu as ‘rich squalor, covering up for the inability to feel and function’. Its denizens live in a ‘kind of spoiled, negligent indifference’. Their ‘anarchy and nihilism will certainly ruin you’.

Hamilton’s volume is perfection of its kind. Her choice of letters is deft, her sensibility is delicate and readers will quiver at the intensity of the exchanges. ‘Whatever choice I might make,’ Lowell tells Hardwick in one of his wobbles, ‘I am walking off the third storey of an unfinished building to the ground.’ So gripping are the clutches of The Dolphin Letters that readers smash at the bottom beside him.