Post-war Germany, of course, has a long tradition of examining what went so horribly wrong after Adolf Hitler's rise to power in 1933, but the grandchildren of those who lived in that dark era are now approaching the past on their own terms.

They are looking for clarity, and often closure, after their parents' generation at turns confronted and kept quiet the complicity of their own fathers and mothers during the Third Reich.

'Things are changing at the moment,' said Himmler, whose book The Himmler Brothers was recently published in English. 'Each generation has to decide how to deal with this legacy.

'Things have been held back for so long. No one wanted to think about it. So the children are the ones who end up having to confront it all.'

Always aware her grandfather Ernst was one of Heinrich Himmler's two brothers, she was compelled to write an unflinching examination of how her family ended up producing the man responsible for carrying out the Holocaust.

She found that Heinrich's siblings, Gebhard and Ernst, weren't simply apolitical technocrats profiting opportunistically from their brother's powerful position as head of the Nazi party's Schutzstaffel - the elite paramilitary organisation commonly known as the SS.

Contrary to her family's commonly held view, both brothers were avid National Socialists sharing the virulent ideology that led Heinrich Himmler to pursue the Final Solution against Europe's Jewry.

The research for the amiable 40-year-old's book eventually caused the side of the family stemming from Gebhard, who lived into the 1980s, to break off contact as their views of their father and grandfather were challenged.

'It wasn't pleasant for my father either, but he perhaps had an easier time because his father had died earlier,' said Himmler.

She explained that she and her sister had always felt the need to come to grips with their heritage beyond what her parents' generation had done.

When asked at age 15 by a classmate during a history lesson whether she was related to Heinrich Himmler, her affirmative reply caused a stony silence to fall over the class.

But instead of seizing the chance to discuss it, her stunned teacher quickly moved on. Himmler felt afterwards that it was a missed opportunity.

An added incentive came after, as fate would have it, she married an Israeli whose Polish family had faced extermination in the genocide carried out by her great-uncle. And once her son was born, she knew she couldn't prolong her parents' silence about her roots.

Like any concerned mother, Himmler still worries about her son's reaction to discovering his convoluted family history. However, writing the book has left her feeling empowered that she now can tell him the whole story.

'Things aren't quite so complicated now. It can all be approached a bit more calmly,' she said.

'The fear is huge at the beginning. But it becomes easier once you've done it.'

The first post-war generation in Germany - that of Himmler's parents - took a decidedly conflicted approach to the country's Nazi legacy.

As part of the 1960s protest movement for civil rights and against the Vietnam War, many young Germans confronted their parents openly about their involvement, both direct and implicit, in the crimes the Nazis committed across Europe. But others just wanted to put it behind them, preferring an uneasy code of silence within their families.

It wasn't until the 1980s that Israeli psychologist Dan Bar-On, whose parents had emigrated from Germany before the war, began groundbreaking research into the often considerable impact of the Holocaust on the children of those responsible for it.

When he revisited his work years later in 2003, Dr Bar-On noted that German society was apparently moving into a new phase: 'The generation of the sixties has matured politically and there is a new need to look into their earlier accusations of their parents' generation, trying now to get closer to 'how could it have happened?''

Although few countries have delved so deeply into the darkest chapters of their history as Germany has, much had remained unresolved at the family level.

During ceremonies marking the 60th anniversary of the end of the second world war two years ago, many commentators in Germany lamented that the number of first-person witnesses to the horrors of that time was dwindling rapidly.

Germans who aren't related to a notorious high-ranking Nazi, unlike Himmler, have also been inspired to embark on their own search into the past.

Jens Schanze, a Munich-based filmmaker, released a documentary in December 2005 exploring his grandfather's role as an ideological water carrier for the Third Reich in Silesia, which is now part of southwestern Poland.

Winter Children - The Silent Generation is his attempt to nudge his family into an open discussion about the actions of his grandfather, who joined the Nazi party as Hitler became chancellor in 1933.

His uncles refused to be a part of the film from the outset and his mother had difficultly judging her father who, like so many Germans of that era, was de-Nazified for a nominal fee after the war. He died in a car accident in 1954 in West Germany long before Schanze was born in 1971.

'It was a taboo topic for my mother,' Schanze said. 'The difference for the generation of the grandchildren is that we can ask questions more for the need to know what happened and less for making judgments.'

That's not to say Schanze is uncritical of his own grandfather just because he was minor party functionary and not a leading Nazi. In fact, he sees him as quite representative of the legions of Germans who allowed the evil inspired by Hitler to run its course.

'It's the millions at the bottom that made the system work,' he said, noting that an opinion poll taken in 2002 showed that a likely unrealistic 49 per cent of Germans believed their ancestors had been critical of Nazism.

Although Schanze's film never definitively answered what ill deeds his grandfather did during the Third Reich other than making anti-Semitic diatribes, it was clear he was at least aware of the concentration camps holding Jews near the family's hometown of Neuroda.

But for the filmmaker, simply breaking the silence within his own family and others is an important step towards finding closure - for both the children of the perpetrators of Nazi crimes and the offspring of the victims of them.

'I believe it's essential - and not just for reconciliation with the descendants of Holocaust survivors,' he said.

'If my generation doesn't deal with what remains unspoken, then it will deeply affect future generations of Germans, Jews and other victims of National Socialism.'

That it's not just younger Germans grappling with the troubled legacy of the war became clear this summer after an Israeli group filed a class-action lawsuit demanding the German government pay for the cost of therapy for the children of Holocaust survivors.

The Fisher Fund, a non-profit group set up to help survivors, claims the trauma experienced in concentration camps such as Auschwitz and Belsen has been passed on to many of their descendants.

'The effect on the second generation has been totally overlooked,' Baruch Mazor, director of the Fisher Fund, said in Tel Aviv.

The group had hoped to negotiate a settlement with German officials, but will now pursue legal action to finance regular therapy sessions for about 15,000 people for several years. Mr Mazor estimated the cost at about Euro100 million (HK$1.1 billion)

Germany, which has paid billions in compensation to victims of the Third Reich over the past decades, is no doubt aware of the implications of any such settlement.

'They are ignoring us. They're afraid people from later generations will stand up all over,' said Mr Mazor.