What a rueful concession for a biographer to make: Ted Hughes remains "her husband," the poet who presided over what — in a remorseful moment — Hughes himself called the murder of Sylvia Plath.

In an exculpatory narrative, Jonathan Bate tries to reverse the momentum of literary history, making Plath the wife of Ted Hughes, poet laureate and winner of virtually all the important poetry prizes. This canny biographer succeeds in his aim, but at a terrible cost to his subject. Plath continues to overpower Hughes on every page. Bate is taken prisoner by her myth even as he tries to rectify the distorted narratives of Plath biographers who put her first.

For Hughes and his biographer, Plath is too much, and every page of this biography on which she does not appear is weakened by her absence — notwithstanding Bate's wit and gift for putting other biographers in their place.

On the final page of his book, Bate declares defeat: Neither Hughes nor his biographer can deny that Plath's death was the "central fact" of the poet's life. In "Birthday Letters," published shortly before his own death, Hughes gave his account of the marriage, declaring his own doom. He was never able to move beyond the boundaries for their lives and poetry that Plath's own writing enforced.

As Bate demonstrates, Hughes began his elegy for himself and Plath not so long after her suicide, but for more than 30 years he could not bear to publish his autobiographical verse, dreading the outcry from those who considered him responsible for her demise.

Bate's narrative is unfortunately dulled all too often by accounts of Hughes' second-rate work. So put out is Bate with Hughes' dramaturgical ineptitude that the biographer offers advice on how the work could have been improved. Bate is conspicuously relieved when he is able to end with Hughes' well received translation of Ovid and the recovery of poetic power all too often stifled in the decades after Plath's death.

But Hughes' culpability in Plath's death ultimately overwhelms the biographer, who seeks out other guilty parties, charging critic Al Alvarez with failing Sylvia at a critical moment when she sought his love. Alvarez, in Bate's roman noir, is also the spurned lover of Assia Wevill, whom Hughes went to when he left Plath. Thus Alvarez's moving account in "The Savage God" of Plath's last days becomes, in Bate's questionable telling, a revenge plot against Hughes, who nobly never exposed Alvarez's role in Plath's death.

That Bate has provided new depth to Ted Hughes' biography and drawn on sources unavailable to other biographers is indisputable, but many of his touted revelations — for example, that Hughes was sleeping with another woman the night Plath died — have been reported elsewhere. (This fact was included in my book, "American Isis: The Life and Art of Sylvia Plath," which was published in 2013.)

He also only hints at shadowy stories in the Hughes archive that are bound to emerge. We still need to know why Hughes — so attractive to women— constantly fell under their thrall as emanations of the "white goddess" he first read about in Robert Graves, who located the origins of civilization in a matriarchy that men would eventually find ways to overturn.

Carl Rollyson is the author of "Amy Lowell Anew: A Biography," and "American Isis: The Life and Art of Sylvia Plath."