JUST IN TIME, Nicola Tyrer has salvaged the last group of unsung heroines of the Second World War: the nurses. Ten years ago, Tyrer exhumed the history of the Land Army Girls who cheerfully drove tractors while farm workers went to fight. But another caucus of women were in much closer touch with the ghastly reality of war: Queen Alexandra's Imperial Military Nursing Service.

The “QAs”, who owed their origin to Florence Nightingale, had been in Boer War field hospitals in their whalebone stays and flowing skirts, and in the same garb at Passchendaele and Gallipoli in the First World War. But in the Second World War they served in battledress, at the front line.

This is a book inspired by baby-boomer guilt. Tyrer was born in 1946. “My parents died before I was old enough - or wise enough - to take any interest in their war service,” she writes. In her 1960s youth, the mantra was peace; Cambridge students boycotted poppy day and the giving of Rag Week money to “militaristic old fools”. Hiroshima and Nagasaki were acts of unparalleled wickedness. Only now does Tyrer regret such glib and ignorant assumptions.

Nine thousand QAs were serving overseas by 1945. They were bombed on hospital trains as they ferried troops from Dunkirk. They tended horribly burnt and mutilated patients, faces hideously disfigured, young lives wrecked. “If a man's foot is cold and gangrenous,” they were advised, “don't waste time, cut it off.”

They sailed for Hong Kong and Singapore expecting adventure, but their hospitals were shelled, and QAs saw the infamous atrocities of the Japanese: nurses were gang-raped, their bodies dumped. “Do English women never cry?” one Japanese interpreter asked. “Not when they have work to do,” Sister Mary Currie replied. Even the Japanese saluted their heroism and stoicism.

Harrowing stories are told with understatement and without self-pity. The Japanese forced a group of nurses to wade into the sea until they were waist-high in the waves, then fired on them; only one survived to tell the tale. “Show them that they can't get you down,” Matron Kathleen Thomson commanded. As PoWs in her care died (of starvation or diphtheria) she stored their names in a talcum powder tin, so that when the war was over she could assure their families that their boys had a Christian burial.

They sailed on overcrowded troopships at the mercy of torpedoes and U-boats. Many QAs were shipwrecked and taken prisoner. Starving, they ate a fish that dropped out of a passing seagull's beak, cooked banana skins, stewed a dead monkey. A nurse wrote to her parents that the experience of being left with nothing taught her “life's true values” and she looked on life as “a great adventure”. By the time her parents received the letter, their daughter was dead.

Hospital ships were supposedly protected from attack, yet ten were sunk; there were never enough lifebelts, and many nurses, leaping overboard into oily shark-infested seas, could not swim. Of the 236 QAs killed in the war, more than half died at sea. In the North African desert among rats, mosquitoes and scorpions, they broiled and froze, subsisting on Maconochie stew, risking fatal infections, their pores clogged with sand, the sun as potent an enemy as Rommel's machineguns.

In Italy, the nurses at Bari witnessed the agonising slow deaths of thousands of Allied soldiers poisoned with American mustard gas, a disaster hushed up until 1993; they nursed the survivors from Monte Cassino, “blinded, jaws and genitals blown off, skulls smashed, limbs severed”.

Hundreds of QAs joined Monty's forces at the D-Day landings, and at concentration camps, ignoring the risk of typhus, nursing skeletal and catatonic inmates either dying or suffering from famine diarrhoea. They stayed until the bitter end, in the Burmese jungle and in India: a caste-bound sepoy would not touch soiled linen, but QAs had no qualms about any patient's needs.

They also sang, danced and put on plays, led hectic social lives (“It was always easy for us Sisters to get a lift in a Jeep”) and found romance, inevitably, being nubile women vastly outnumbered by virile young men. Wherever they arrived, they boosted morale.

The few remaining survivors, who still meet today, remember that however terrible war is, they had comradeship and learnt to live without “all the things in England we deem indispensable”. Coming home to civvy street was dreary, flat, an anti-climax. Reading these stories of iron discipline, resource and self-sacrifice in women of 20 or so, I wonder how my generation would have coped.

There is certainly no link, other than age, between the QAs and the Amy Winehouse generation. Tyrer's prose, stripped of purple passage or poetic flourish, reflects a brisk journalistic commitment to gathering the last testimonies in a tale well worth telling.

Sisters in Arms: British Army Nurses Tell Their Story by Nicola Tyrer

Weidenfeld & Nicolson, £20; 320pp

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