In her perceptive, exhaustively researched biography of Siegfried Sassoon, Jean Moorcroft Wilson posits that “a study of his life is a study of his age” (Siegfried Sassoon: Soldier, Poet, Lover, Friend, Overlook Duckworth, $40, 629 pp.). In fact Sassoon’s life spanned several ages. When he was born in 1886, Victoria was Queen and William Gladstone had just introduced the first Irish Home Rule Bill. Gilbert and Sullivan ruled the London stage. Across the English Channel, Otto Von Bismarck, chancellor of a Germany that was largely his creation, had helped bring about a balance of power designed to secure a continent-wide peace.

When Sassoon died in 1967, the British Empire was a memory. After two devastating wars, Europe was divided between East and West. The threat of mutually assured destruction maintained a fragile peace between the United States and the Soviet Union. In England, the Beatles released the psychedelic genie with Sgt. Pepper’s Lonely Hearts Club Band. The sexual revolution was in full swing. Parliament decriminalized homosexuality.

Sassoon was indeed, as Wilson accurately sums him up, “Soldier, Poet, Lover, Friend.” But, like Walt Whitman, a poet he was greatly influenced by, Sassoon was a man of contradictions, large in spirit, able to “contain multitudes.” At one time or another, he was war hero, war resister, country squire, snob, socialist, novelist, memoirist, homosexual, husband, father, spiritual pilgrim, and, near the end, a convert to Catholicism.

T. E. Lawrence, a friend of Sassoon’s, once said that if he had to send a representative Englishman to an international exhibit of human specimens, he’d choose Sassoon. Yet as much as he was an embodiment of Englishness (at least one version of it), his name gave no hint.

The Sassoons were originally Jewish merchants in Baghdad whose success led them to be referred to as “the Rothschilds of the East.” They continued to flourish after moving their headquarters to Bombay. In 1858, they opened a London branch headed by David, Sassoon’s grandfather. Though they remained Orthodox Jews, David and his family quickly adapted to English ways, purchasing the “splendid Elizabethan mansion” in which Siegfried’s father, Alfred, was raised.

His mother, Theresa Thornycraft, the daughter of landed gentry with a strong artistic streak, chose the Teutonic-sounding Siegfried. A sculptress and painter, eight years Alfred’s senior, Theresa was a passionate admirer of Richard Wagner. Alfred and she were married in the Anglican Church, an act of apostasy on Alfred’s part that scandalized his family and led his mother to “curse any children born of what she saw as an unholy union.”

Siegfried was the second of three sons. His parents settled in Weirleigh, a country house in Kent. Supported by a staff of servants, they enjoyed a genteel, upper-class existence that orbited around fox hunting, cricket, country fairs, garden shows, and formal dances. It was a social scene that hadn’t changed much since the days of Jane Austen. But Theresa had intellectual ambitions for her sons that went beyond the rural pastimes of the squirearchy. For Siegfried’s third birthday, she gave him a copy of Coleridge’s lectures on Shakespeare.

Although their marriage seemed happy at first, Alfred grew bored and restless, and seemed possessed of a roving eye. He left Weirleigh for London in 1893. Siegfried bore the effects of his parents’ breakup for the rest of his life. Alfred died of TB when Siegfried was nine. Bereft of a husband, Theresa kept her sons close. Siegfried was educated at home until he was thirteen, and when he went away, his mother made sure the school was close by.

A typical schoolboy from a respectable though not aristocratic background, he was a middling student. His greatest passion was cricket, a game in which his interest never waned. In the all-male setting of an English public school, he became fully aware that “women were ‘antipathetic’” to him and that his sexual attraction was to men. His teachers’ judged him lackadaisical and saw little if any potential, concluding that he “lacks power of concentration; shows no particular intelligence or aptitude for any branch of his work; seems unlikely to adopt any special career.”

Sassoon’s years at Cambridge seemed to bear out their dismissive appraisal. He spent most of his time riding and playing cricket, and pursuing a newfound passion for golf. His academic performance was unimpressive. The only exception was a flowering of his interest in poetry. He left after two years without a degree but with enough poems to self-publish a collection, appositely titled Poems.

He returned to Weirleigh and re-entered a relaxed country life bounded by the gentry’s familiar sporting pursuits and the usual rounds of socializing. There was nothing to indicate that he wouldn’t sink back into the life of a country gentleman, without “any special career,” except for two deep-seated urges he couldn’t satisfy in the staid, conventional Kentish countryside.

Sexually as well as intellectually, he was restive in a place in which poetry was considered a frivolous eccentricity and homosexuality a base and legally banned perversity. His interest in poetry deepened. He wrote in “late-Romantic” style and admired the formality of Rupert Brooke and Robert Graves. (T. S. Eliot, Wilson tells us, “became Sassoon’s particular bête noir,” and Pound and Yeats weren’t far behind.) Without entirely abandoning the safe, familiar precincts of Kent, he spent more and more time in the cosmopolitan atmosphere of London.

It’s possible that in an earlier age, when a gentleman who made no flamboyant displays of his proclivities might have his privacy respected, Sassoon could have sustained a double life. All that changed with the outbreak of war in 1914. The war blew Sassoon out of his comfortable, cosseted world. It exposed him to classes, people, and experiences he would have otherwise never encountered; made him a hero and a rebel; and from the perspective of his ambitions as a writer, “gave him a genuine subject for his poetry.”

At first, like most civilians on both sides of the conflict, Sassoon responded with “unquestioning idealism.” He was commissioned in the Royal Welch Fusiliers. His desire to see action wasn’t diminished by the unfolding stalemate manifested in the jagged scar of trenches and barbed wire that marred the landscape for four hundred seventy-five continuous miles, from the English Channel to the Swiss border.

The first jolt to Sassoon’s perception of the war as glorious crusade came in November 1915 with the news of his beloved younger brother’s death at Gallipoli. His reaction wasn’t to turn against the war but to express a desire for revenge: “I see your laurell’d head / And through your victory I shall win the light.” That same month his regiment shipped out for France.

Wilson points out a certain irony in the intimate association that developed between Sassoon’s fame as a poet and his time in the trenches: “Remarkable though it may seem, Sassoon, who was in the army from the day the war broke out to the day it ended and had the reputation of being a fire-eater, spent barely a month out of a possible fifty-one in the Front Line.”

Measured in days, that span was brief. But it was sufficient for him to be wounded twice, participate in three of the war’s costliest battles—the Somme, Arras, and Passchendaele—and be awarded the Military Cross. He emerged not only a different man but a poet of real stature, his vocabulary “simple and unrhetorical,” infused with a power it never had before.

The Royal Welch Fusiliers went into the trenches in March 1916 as the British high command amassed a force of men and artillery sufficient to smash through the German defenses at the Somme and produce a decisive victory. While preparations went on, Sassoon’s hunger for action and his readiness to venture into no man’s land won him the moniker “Mad Jack.”

His fearlessness and abiding concern for the men under his command earned him their respect and loyalty. He in turn admired the everyday perseverance of ordinary, working-class Tommies with whom, in peacetime, he had little contact. His poetry drew on the mud and dread that filled the trenches; images of “laurell’d” heads gave way to rats gnawing on the remains strewn across no man’s land: “The sentry keeps his watch where no one stirs / But the brown rats, the nimble scavengers.”

The battle of the Somme began on the morning of July 1, 1916. Sassoon and his men were held in reserve until the third day. They quickly found themselves in a battlescape of unspeakable carnage: dismembered limbs, bullet-ridden bodies, abandoned guns, rifles, knapsacks, helmets, and boots splattered with brains and intestines.

Even at a century’s distance, it is hard to encapsulate the horror of what took place as a hundred thousand British troops assaulted the German lines. The greatest artillery bombardment in history preceded them. Sheltered in well-constructed dugouts and trenches, the Germans emerged to lay down a withering hail of fire that killed twenty thousand of the attackers within the first hours and left another forty thousand wounded. In some places, the Germans stopped firing so the wounded could crawl away.

Sassoon survived the Somme and was sent home to recover from trench fever. The civilian complacency he encountered fueled his indignation over what he’d witnessed across the Channel. He grew furious at the willingness of press and politicians to mask the slaughter as “willing sacrifice” by soldiers who’d been little more than “compressed cannon fodder.” In reaction to a speech given by the bishop of London on the transformative effect of war, he wrote:

“We’re none of us the same!” the boys reply.

“For George lost both his legs: and Bill’s stone blind;

“Poor Jim’s shot through the lungs and like to die;

“And Bert’s gone syphilitic: you’ll not find

“A chap who’s served that hasn’t found some change.”

And the Bishop said: “The ways of God are strange!”

He returned to the trenches in February 1917. More disillusioned than ever by the indifference and ignorance he found at home, he arrived in time for the battle of Arras. Once again, a massive assault was met with fierce resistance. The dead were trampled in the mud. The ground itself oozed with the putrid mush of rotting corpses. In Sassoon’s formulation, the troops no longer prayed for victory but for a way out: “O Jesus, send me a wound to-day, / And I’ll believe in Your bread and wine, / And get my bloody old sins washed white.”

Struck by a bullet that just missed his jugular, he was sent home to recuperate. Discontent simmered into rage: “I’m back again from hell / With loathsome thoughts to sell.” His dark mood lifted somewhat with the debut of The Old Huntsman, a collection of poems written between 1907 and 1917. It was his first commercially published book. The bold, bitter antiwar sentiments of the latter poems caused a sensation. Suddenly the leading lights in the literary establishment were eager to meet him.

His newfound fame did nothing to soothe his anger. At the beginning of July, he notified his commanding officer of his refusal to serve: “I have seen and endured the suffering of the troops, and I can no longer be a party to prolonging those sufferings for ends which I believe to be evil and unjust.” He expressed his hope that his formal protest “may help to destroy the callous complacency with which those at home regard the continuances of agonies which they do not share and which they have not sufficient imagination to realize.”

He threw his medal for bravery into the Mersey River. He knew he faced court martial and imprisonment. Yet what he feared most was that instead of being recognized as a cri de coeur on behalf of those already dead and those about to die, his non serviam would brand him a shirker and a coward. Some did condemn his decision outright. His friend and fellow officer Robert Graves deemed it “not good form” and “beneath the dignity of an officer and a gentleman.” Others were silently sympathetic.

His military superiors faced a quandary of their own. Cashiering and jailing a decorated, admired officer like Sassoon might serve to amplify his protest and encourage others to follow. A way out was offered by a decision of a Royal Army Medical Board to classify him as the victim of a war-inspired mental breakdown and send him for appropriate treatment.

Torn between what he held was the righteousness of his protest and his guilt at the soldiers he’d left behind, Sassoon agreed to be sent to Craiglockhart, a military convalescent home outside Edinburgh. Though he found it gloomy and depressing, its hallways echoing at night with the cries and mutterings of sunken-eyed soldiers haunted by the horrors of the front, he was buoyed by two friendships that he made there.

W. H. R. Rivers, his case doctor, was an eminent neurologist who proved sympathetic and made no effort to argue him out of his views. Sassoon came to trust and admire him. One day Wilfred Owen, a short, seemingly timid officer who was also being treated by Rivers, visited Sassoon. A would-be poet, as yet unpublished, Owen appeared humbled to be in the presence of a writer of Sassoon’s stature. (Pat Barker’s award-winning trilogy of novels—Regeneration, The Eye in the Door, and The Ghost Road—is a fictionalized account of the relationship among Sassoon, Owen, and Rivers.)

Not long after, Owen asked Sassoon to look at a sonnet he’d written. Sassoon immediately recognized Owen’s potential and generously offered to help perfect what would become “Anthem for Doomed Youth.” (“What passing-bells for those who die as cattle? / —Only the monstrous anger of the guns.”)

The extraordinary coincidence of two of the war’s greatest poets being together in the same convalescent home proved beneficial to both. They traded ideas and published poems in Craiglockhart’s in-house magazine. Wilson surmises that Owen’s feelings may have tipped over into love. Sassoon saw himself as a mentor, not a lover. When Owen was killed in the last week of the war, Sassoon mourned the loss of his friendship and his talent.

Sassoon could probably have sat out the rest of the war. His attachment to the men he’d left behind precluded that. (“Love drove me to rebel. / Love drives me back to grope with them through hell.”) He stifled his true feelings when re-examined by the Medical Board and was found fit to return to service.

After detours to imperial trouble spots in Ireland and Palestine, he was shipped to Flanders, where the Allies struggled to defeat the last great German offensive. The terrain was familiar; the proximity of death the same. Utterly drained of any patriotic feeling and convinced he was destined to die, Sassoon affirmed his willingness to share the fate of his men:

I stood with the Dead...They were dead; they were dead;

My heart and my head beat a march of dismay:

And gusts of wind came dulled by the guns.

“Fall in!” I shouted; “Fall in for your pay!”

As the battle of Passchendaele raged on, Sassoon once more lived up to his reputation as Mad Jack, leading raiding parties, fearlessly exposing himself to enemy fire, comforting and encouraging his men. Finally, on a scouting mission, he was grazed by a bullet that came close to blowing his head apart. He was hospitalized and sent home. His war was over.

It is one of the engaging aspects of Sassoon’s life, as well as one of the many strengths of Wilson’s account of it, that though the war transformed Sassoon as an artist and a man, it was in no sense a finale. He lived for five more decades. If none matched the concentrated drama of the war years, they were filled with a personal struggle that resonates with the doubts, hopes, ambitions, and anxieties that World War I spawned and that are with us yet.

The first result, which was widely shared, was “an awareness of life’s transcendence” and a resolve “to seize the moment’s passion.” Sassoon put aside the mask of sexual detachment. The tight rein on his desires that he’d kept in the army fell away. The war highlighted that life and its pleasures were precious and to be enjoyed:

You’ve got your limitations; let them sing,

And all your life will waken with a cry:

Why should you halt when rapture’s on the wing

And you’ve no limit but the cloud-flocked sky?...

He began a series of affairs, preferring blond, handsome men, significantly younger than he was, before settling into a relationship with a young officer whose nickname of Gabriel reflected his angelic looks. As open as Sassoon was with his friends about his homosexuality, he was still required to be discreet in public.

The war’s end removed any danger of him being viewed as a would-be traitor or seditious malcontent. Instead of unseemly and cowardly, his public protest was seen as a prophetic indictment of industrialized murder and the futility of modern war. He was welcomed into the inner circles of the cognoscenti and literati. His acquaintances grew to include Lytton Strachey, Virginia Woolf, Robert Bridges, John Maynard Keynes, Aldous Huxley, John Masefield, John Galsworthy, E. M. Forster, T. E. Lawrence, et al. Even Winston Churchill sought him out.

He had a brief fling with socialism. He joined the Labour Party and took on the post of literary editor of the staunchly left-wing Daily Herald. But politics bored him. Despite the genuine sympathies instilled by his wartime experiences with ordinary workers, he remained a man of the upper classes who never shed the prejudices of his caste.

In 1920, he ventured on a speaking tour to America. Repulsed at first by Jazz Age New York, he came to enjoy it. Poet Louis Untermeyer and playwright S. N. Behrman befriended him. For one of the few times in his life, he identified with his Jewish roots. He had a passionate affair with an actor. He read his poems in lecture halls and Ivy League colleges. Everywhere he was greeted warmly and treated as a celebrity.

As quickly as fame came, it slipped away. Back in London, Modernism was triumphant. He was unable or unwilling to abandon traditional verse. As much as he hated war, he was bereft of material sufficient to motivate him to write. He was “as dry as a biscuit,” he lamented. He retreated to Weirleigh and found solace in its pleasant diversions. He began writing a roman à clef based on his early life and the bucolic idyll he recalled (and in part imagined).

His contradictions were as apparent as ever. He wavered between enjoying the obscurity of country life and lusting after celebrity. Driven by his self-described “priapismic devils,” he was relentless in his pursuit of sex. Yet he yearned for quiet and solitude. In the midst of this inner turmoil, he penned lines that he believed expressed his deepest longing:

Alone...The word is life endured and known.

It is the stillness where our spirits walk

And all but inmost faith is overthrown.

The publication of Memoirs of a Fox-Hunting Man, the first of three semi-autobiographical novels, proved a critical and financial success. It soothed his bruised feelings at the way his poetry was ignored. Around the same time, Stephen Tennant entered his life. The fourth son of Lord Glenconner, Tennant was rich, beautiful, and a prominent member of “The Bright Young Things,” the frivolous, privileged set that delighted in scandalizing traditional society. Many regard him as the model for Sebastian Flyte in Evelyn Waugh’s Brideshead Revisited.

Sassoon was forty-one when they met; Tennant twenty-one. “You are the person I’ve most loved in my life,” Sassoon told him. Their first years together were blissful. They traveled across Europe, stayed in villas, chateaux, and grand hotels. Sassoon remained infatuated. But the inconsequentiality of Tennant’s pursuits and interests was increasingly grating. It was impossible to engage him in serious conversation about art or music or literature.

It was Tennant who called off the affair. He resented Sassoon’s criticisms of his directionless, sybaritic ways. Sassoon was devastated. He begged to be taken back but was rebuffed. The only relief from the heartbreak was burying himself in writing the second novel in his trilogy, Memoirs of an Infantry Officer.

Once again—this time in the form of Hester Gatty, a slim, bright, attractive woman in her late twenties—Sassoon’s life took an unexpected turn. He’d never been in love with a woman before. Now he was. There are any number of speculative explanations for this sudden switch in sexual preferences—a change of heart, a hunger for respectability, a deep-felt desire for children, nostalgia for the domesticity he knew as a young boy at Weirleigh, the wish to get back at Tennant. Nobody can say for sure. To her credit, Wilson doesn’t try.

Sassoon didn’t hide his former life from Gatty, and she, already an admirer of his work, was unfazed. They were married on December 18, 1933. Soon after, they set up house in Heytesbury, a sprawling country house, set amid 220 acres of park and woodlands, with 17 bedrooms and a separate wing for servants.

In one of the photographs Wilson includes in the book, Sassoon sits high in the saddle. He wears a riding coat and top hat, the very picture of the fox-hunting man. Hester stands in front, her face creased by a wide smile. Their happiness is obvious. His spirits were further lifted by the completion of Sherston’s Progress, the third novel in his trilogy, and reached “unimaginable heights” with Hester’s pregnancy and the birth of their son, George.

Their happy days were short lived. He spent much of the day alone with his writing. The hours that were left he devoted to George. She felt neglected and sought his attention. He resented her “possessiveness.” They bickered and fought. She spent more and more time away from Heytesbury, which he not only welcomed but insisted on.

The rise of fascism and Nazism reinforced his unhappiness. When war finally came, he described himself as “a semi-submerged barge on a derelict canal.” Heytesbury was partly requisitioned to quarter military personnel, but Sassoon recused himself from pitching in on the home front. He had had his fill of war. He worked away on his three-volume memoir. “The only effective answer that a poet can make to barbarism is poetry,” he wrote, “for the only answer to death is the life of the spirit.”

Hester left him for good in 1944. The war’s end brought no relief. He contemplated suicide but rejected it in consideration of his son. His dejection deepened with the poor reviews that followed publication in 1947 of his collected poems. The drab atmosphere of postwar Britain oppressed him. His flirtation with socialism long behind him, he resented the social leveling brought about by the Labour government.

As his world shrank, his poetry took a distinctly spiritual turn. “Befriending Star,” a poem included in the three privately published collections he completed between 1950 and 1954, framed his quest:

                             Heart-simplified, appear

Not in ferocity of elemental fire,

But, for my lowly faith, a sign by which to steer.

No sign appeared. In “Faith Unfulfilled,” he wrote of a desire for God, deeply felt but unrealized:

Deaf, eclipsed, and dumb,

Through this gloom I come

On the time-path trod

Toward ungranted God.

The time-path grew only stonier and steeper. He suffered the passing of old friends and the conviction that his years of writing were all for nothing, bringing only neglect and obscurity. When Sequences, a trade edition of his recent poems was published in 1957, his worst fears were realized. It was largely ignored or brushed off as stodgy and out of date.

His life, however, took one final and unexpected turn. Sequences came into the hands of Mother Margaret Mary McFarlin, superior of the Convent of the Assumption in London. Sensitive, intelligent, devout without being pietistic or judgmental, she wrote to praise his book. He might have been amused by the novelty of a letter from a nun and let it go at that. But he responded, and they soon began a serious correspondence around their shared love of Gerard Manly Hopkins, Robert Browning, and the metaphysical poets. She strongly recommended to him the writings of John Henry Newman.

His response to Newman was immediate and unequivocal: “All clear as daylight. And as simple as falling off a log—just unequivocal surrender.” He started religious instruction with the Benedictine monks at Downside Abbey, not far from Heytesbury, and was helped along by Mother Margaret Mary and, especially, by Msgr. Ronald Knox, a convert himself and the former Catholic chaplain at Oxford. (Sassoon and he are buried close to one another in Mells, in Somerset.)

“When Sassoon was received into the church at Downside on 14 August 1959, the eve of the Feast of the Assumption,” Wilson concludes, “it was the culmination of years of thought and reading. Yet his inward experience during the next few days seemed to him ‘something unfathomable by the mind.’ He ‘just allowed it to happen, knowing and yet unknowing.’”

He fretted over how friends might react. He needn’t have worried. With one or two minor exceptions, they were happy to see him content rather than sunk in despair. The last decade of his life was felicitous. The fiftieth anniversary of World War I, the rising tensions around the Cold War, the raging war in Vietnam gave his antiwar poetry new relevance and prominence. Oxford bestowed an honorary degree. The BBC marked his eightieth birthday with a special program.

He continued to find comfort in his faith. Diagnosed with inoperable stomach cancer, he assured his son, “This is the final test of my endurance and I intend to put up a good show.” He died in his own bed on September 1, 1967.

Siegfried Sassoon isn’t as easy a man to categorize—and perhaps oversimplify—as, say, contemporaries like Winston Churchill (statesman) or T. S. Eliot (poet) or Evelyn Waugh (novelist). Sassoon’s life sprawls and twists and curves with wild unpredictability. There were times he savored, times he barely survived, times he wandered, unmoored and befuddled, always in seeming pursuit of some enduring source of meaning and purpose that eluded him, like a sly, cunning fox.

The sole consistent theme in Sassoon’s life was a spiritual search to be “finally at peace with himself and the world.” Wilson’s memorable and admirable recounting of his life leaves little doubt he succeeded, his inmost faith intact.