Sixty years ago, when I arrived in southern Germany in April 1945, to help to set up centres for abandoned children with the United Nations Relief and Rehabilitation Administration, it was weeks before I first heard Hitler mentioned. It finally happened on May 2, at 2am, in a large school gymnasium, where, my torch the only light, I sat at a small table surrounded by several hundred children restlessly sleeping on straw pallets. Every few minutes one of them would cry, or call out, in one of their own languages, or in the German they had learnt in years of occupation and forced labour. I would go and hold their hands or hug them.

These were just a few of tens of thousands of the youngest of Hitler’s victims we eventually found, in camps, foster families or wandering on the roads. Miguel, a gentle Chilean doctor, sat next to me, holding a boy of maybe five we had found in a ditch that day, a tattooed number on his arm identifying him as a concentration camp inmate. “That monster Hitler, their damned damned Führer,” Miguel said softly, rocking the catatonically silent child to sleep.

One would have thought he’d be ever-present in our minds, but the truth is that in that early period it was the consequences of Hitler’s rule that occupied us, not his personality, his private or working life, and certainly not his just announced death in his bunker.

Now, of course, when millions of words have been written about him, I know that one of his many obsessions was bunkers. As early as 1935, six bunkers of immense proportions, capable of receiving many thousands of civilians, were built on his orders under Berlin, and later one under each of his four field headquarters. There were also three large shelters below the Reich Chancellery, one for the drivers, the largest for the Chancellery’s thousands of personnel and finally — added in 1944 with two constructions at a much deeper level, 14m (46ft) under the earth — the Führerbunker.

The higher part was the Vor (front) bunker with four rooms for Goebbels’s family, two for servants, a kitchen and living/dining room, sanitary facilities and utility spaces for the control of water, heat and electricity. Guards controlled access to the lower part 2.5m further down, connected by a spiral staircase, containing 19 cell-like bedrooms and studies, a sick bay, and washrooms and lavatories for Hitler, Eva Braun and Goebbels.

Starting in 1947 with Hugh Trevor-Roper’s now classic The Last Days of Hitler, untold numbers of articles and eight books have been devoted to Hitler’s final weeks. Among them, James P. O’Donnell and Uwe Bahnsen’s excellent 1975 The Catacombs: The Last Days, Anton Joachimsthaler’s meticulous The Last Days of Hitler published in 1999, and the 2002 memoirs of Traudl Junge — Hitler’s youngest and, from my experience, most intelligent secretary — Until the Final Hour.

Given just these three books and their wealth of detail, I pondered what moved Joachim Fest, one of Germany’s leading Third Reich historians, to present his book, Inside Hitler’s Bunker, when all the witnesses are dead and nothing new can be added.

Of course, many writers, myself included, have felt irresistibly drawn towards the Nazi period. What intrigued most of us was, and still is, the contradictory personality of Hitler himself, a kind of “Everyman” without whose terrifying charisma and talents — not as a statesman but as a politician — 30 million people would not have died.

But, as I read Fest’s book, I came to understand that it was not really Hitler himself — about whom, after all, he had written a well-received biography in 1973 — that motivated him. For while he describes the now familiar main events inside the bunker (the Führer’s birthday, marriage to Eva Braun, the killing of Goebbels’s six children), these dramas are not really the purpose of the book. Nor, indeed, are they Fest’s strength: others have done it better.

What is surprisingly telling in this short book is Fest’s factual accounts of the suicidal battles Hitler ordered fought for Berlin. Fest shows us Hitler’s contradictory last-minute decisions, his grotesque orders screamed into his bunker telephone even when the Russian troops were only a few streets away. Here are the farcical twice-daily military situation conferences attended on pain of death by his shattered generals. Here is their dismay at his physical and mental disintegration and yet — this perhaps the most tragic proof of his charisma — also their obedience to his insane strategic orders and the apparent eagerness of the troops to carry them out. Even though (seen against the 200 pages Ian Kershaw devotes to those weeks in his monumental Hitler) it is written in a kind of shorthand, Fest’s description of the chaos of these battles makes the whole book worthwhile.

Not so, however, his conclusion about Hitler’s personality, which, suggested with just one sentence 30 years ago in his biography, now permeates this book. Hitler’s deepest need, he says, echoing in my mind an outdated Anglo-American populism, was to destroy: he hated the world and thirsted for exterminations.

Such pop analysis of an infinitely complex man who — precisely because of the contradictory aspects of his character — managed to persuade at one point not only the Germans but half of Europe to join him in his delusions is, it seems to me, unworthy of Fest.

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