Martha Gellhorn, who died in 1998 aged eighty-nine, made it her business to speak on behalf of victims of war, poverty and callous governments. There was no shortage of such people in a life which spanned the Great Depression, the Spanish Civil War, two world wars, and the conflict in Vietnam which made her feel ashamed to be American and resulted in her permanent exile in Britain.

As a fearless twenty-two year old with tremendous faith in humanity, she sailed to Paris and offered her services as a reporter to the bureau chief of the New York Times, believing at this point that journalism could be a “guiding light”, the beam of which could alter public opinion. This axiom sustained her until she visited Dachau, in the immediate aftermath of the Allied liberation. That day, Caroline Moorehead notes in her splendid biography, Gellhorn lost her belief that “truth, justice and kindness would always, in the end, prevail”.

She did not however lose one ounce of her courage or her sense of outrage, both of which underpinned her entire life. Moorehead, whose parents were close friends of Gellhorn’s, brings to her biography an affectionate and profound understanding of her subject, which does not preclude criticism of Gellhorn’s ample failings as a journalist, friend, mother and wife. But her comments on Gellhorn’s sometimes lamentable behaviour have none of the sly moral censure that marred Carl Rollyson’s biography of 2001.

Gellhorn, who did her best to obstruct Rollyson, called it a “paean of hate”. It is astonishing how many times Rollyson refers to her striking blonde hair, long legs and casual elegance, implying that she depended on her good looks, not only as a war correspondent, but also to ensnare H. G. Wells and Ernest Hemingway, both of whom, he suggests, she used to advance her own career.

Gellhorn angrily denied that she had ever slept with Wells, and Moorehead convincingly sets out the basis of their friendship: “fondness and admiration on Martha’s part, and . . . fanciful infatuation on his”. Moorehead, who had access to all of Gellhorn’s extant correspondence and diaries, does not indulge in speculation, and at times rather impassively recounts Gellhorn’s numerous affairs and abortions, notwithstanding her curious inability to enjoy sex. She is scrupulously even-handed on Gellhorn’s five-year marriage to Hemingway and sets the record straight on the supposed marriage to Bertrand Juvenal. Gellhorn did on occasion use his surname, but that may have been to appease her parents who strongly disapproved of her relationship with the already married Frenchman.

Gellhorn’s parents were a politically liberal, happily married couple who figured large in St Louis community life. Her father, a half-Jewish German émigré doctor, had progressive ideas about health, hygiene and education, and her mother, Edna, was an active suffragette. When George discovered that his twelve-year-old daughter’s biology textbook did not detail genitalia, the Gellhorns helped establish a new, co-educational school in St Louis, where the sexes were treated as equals and gardening was on the curriculum.

Martha gained verve, confidence and curiosity from the examples of her parents. But their expectations and standards were hard to live up to, and she often despaired about her writing ability. (This did not prevent her from ruefully noting, when in her 50s, that she was being overtaken by John Updike and Saul Bellow.) George was her harshest critic: in one letter he expresses his relief that Martha’s affair with “that little French runt” is over; and by way of encouraging her to write, urges: “it’s you and only you that can pull you out of this slough of self-pity and self-abasement and make you a person of lasting worth”.

Edna was less conditional in her love and Martha relied heavily on her support, once, with her usual tactless honesty, telling her adopted son, Sandy, that she loved her mother more than anyone else. Moorehead does not spare us the full painful story of Martha Gellhorn’s bungled relationship with Sandy, whom she went to great lengths to adopt from an Italian orphanage in 1949.

Work always mattered most to Gellhorn; it made her feel alive. She published a dozen books of fiction and co-wrote a play, but, as Moorehead observes, she was a better journalist. Her intent was always to expose the civilian miseries of war, and though notably lacking in political analysis her dispatches have a piercing clarity largely absent in the work of modern embedded correspondents. She could be cannily prescient: in 1938 she thought that Chamberlain was the “most hateful figure in modern times”, and in 1945 she predicted a “Russo-American war”.

The best of her war reportage has been collected in The Face of War (1959) and The View from the Ground (1988) and pungently demonstrates her dismissal of “all that objectivity shit”. No where is this more evident than in her impassioned reports about Israel after the Six Day War in which she excoriates the Arabs, a position she never relinquished.

Gellhorn was probably more afraid of boredom than death, which made her an excellent war correspondent, but an intemperate friend. She none the less had the gift, as Moorehead so disarmingly puts it, of making you “feel a little better about yourself”. This 500-page biography, in which twentieth-century history is rendered as vividly as the life, is both admirable and remarkably short.

First published in the TLS.