“My experiences in the First World War have haunted me all my life,” Edmund Blunden confessed the year before he died, “and for many days I have, it seemed, lived in that world rather than this.” Siegfried Sassoon felt much the same, and despite producing many volumes of verse on other topics both men would continue to be fêted as war poets.

In contrast, the war was a major part of the All That to which their erstwhile friend and fellow soldier Robert Graves attempted to say Good-bye in his celebrated 1929 memoir, and he would thereafter excise his war poetry from selected and collected editions of his poems. As a result, this poetry is less well known than that of his peers. Charles Mundye’s excellent Robert Graves: War Poems (2016) showed just how many of them there were, and this first volume of Jean Moorcroft Wilson’s new biography convincingly makes the case for Graves as a major war poet, however much he attempted to escape that role.

Although Graves sometimes wrote poetry as brutally realistic as Sassoon or Owen, his 1917 volume bore the title Fairies and Fusiliers, and when writing about the war he often went back to his childhood or drew upon mythology, ancient history and the world of dreams. These were themes that he would embrace in his later career; more immediately they resulted in poems that at their best are both effective and affecting: “Dead Cow Farm”, “Goliath and David”, “The Legion”, “A Child’s Nightmare”. He prepared a further volume titled The Patchwork Flag, in which (as he put it) “occasional corpses […] blunder up among the nursery toys”, and it was this uneasy mix between the battlefield and the playpen that led Sassoon to advise Graves against its publication.

That Graves would follow Sassoon’s counsel was an indication of their closeness, although the publication of Graves’s lively but unreliable memoir put an end to their friendship. A copy furiously annotated by Sassoon and Blunden was intended for the British Library, and Sassoon’s own copy, recently discovered and similarly marked up, shows that his disgust at Graves’s errors and indiscretions had not dissipated.

It is interesting to compare Moorcroft Wilson’s account here of this crucial friendship and its sad unravelling with the one given in her earlier biography of Sassoon. Perhaps because Graves is now her focus, she gives rather less detail about his often disgraceful treatment of Sassoon, but she does not attempt to gloss over his notorious tactlessness. “I have very little of what is called ‘ordinary imagination’,” Graves said; “it often does not occur to me that people can possibly have strong feelings about things which appear to me perfectly trivial.” Moorcroft Wilson finds this “a remarkable admission from one of the greatest imaginations of the 20th century”, but it seems all too characteristic that Graves should by implication dismiss the sensitivities of others as merely “ordinary” imagination, existing at some less exalted level than his own.

While broadly sympathetic, Moorcroft Wilson also remains rightly sceptical, frequently using the verb “claimed” when reporting things Graves has said or written and gently showing how chronology often fails to support his assertions. She nevertheless observes that “the ‘truth’ to Graves, as Good-bye to All That would make plain, was not factual so much as emotional, that is, how it felt to Graves himself.”

How things felt to Graves tended to trump all other considerations, and while his determination to live as a poet may have been courageous, a highly developed sense of entitlement meant he was happy to rely upon often substantial handouts from family and friends in order to pursue this calling, and did not always consider gratitude necessary. He could also be boastful and arrogant, as when he claimed to have “found” Wilfred Owen (who declared, “No thanks, Captain Graves! I’ll find myself in due time.”) and proceeded to lecture him on “irregularities” in his poetry – in the course of which, Moorcroft Wilson notes, he inadvertently exposed his own technical conservatism.

The last 100 pages of this entertaining and finely detailed biography introduce the person Graves considered his salvation, though others thought her his nemesis. Laura Riding entered his life in January 1926 and would dominate it for some 13 years. Invoking Dryden’s version of the Antony and Cleopatra story, Moorcroft Wilson suggests that Graves considered “the World Well Lost” when he took up with this truly appalling woman, even though it was at the cost of most of his friends and all of his dignity.

Riding claimed to be some kind of goddess capable of stopping time itself, but revealed her true nature by throwing herself to the ground in a hotel foyer, screaming and kicking, when she failed to get her own way. Jumping out of a fourth-floor window under similar provocation nearly did for her, but she survived to alienate still more of Graves’s friends and family and to accompany him to Majorca. It was here that Graves would make his home and have a hugely prolific career, not only as a poet but the author of several best-selling prose works; but his second war of attrition, this time romantic, was just about to start.

Peter Parker is the author of “Housman Country: Into the Heart of England” (Little Brown)

Robert Graves: From Great War Poet to Good-bye to All That (1895-1929)

Jean Moorcroft Wilson

Bloomsbury, 461pp, £25