Almost seven decades since Nazi Germany decimated Poland's Jews in death camps like the notorious Auschwitz, Europe's former Jewish heartland is reconnecting with a lost part of its identity.

The communists who took over after World War II imposed a wall of silence on a century of Jewish life here, but this has steadily crumbled since the regime's collapse in 1989.

Today, cultural festivals, cemetery restoration programs across Poland, school Jewish history classes, national commemorations and burgeoning academic research are reclaiming the past.

"Actually the fact there was silence for 50 years, 20 years later many people have a greater appreciation of the role of Jews -- that's a very fast change," Poland's Chief Rabbi Michael Schudrich told AFP.

On the eve of the German invasion in 1939, Poland was home to Europe's largest Jewish community -- around 3.2 million people, representing 9-10 percent of the country's total population in the 1931 census.

Half of the six million Jews killed in the Holocaust were Polish. Most died in camps set up by the Germans in occupied Poland, such as Auschwitz-Birkenau, which has come to symbolize Nazi genocide, and whose January 27, 1945 liberation is being commemorated this week.

By early 1946, a year after the end of the war, Poland's Jews numbered only around 200,000, according to the Polish statistics office.

Most emigrated amid the creation of Israel in 1948, or during anti-Semitic campaigns by the communist regime in the 1950s and 1960s sparked in part by power struggles within the ruling party.

"Up until the 1990s there was no way to have an open, public and broad discussion on these issues, because of communism," said French academic Jean-Yves Potel, author of the 2009 work "The End of Innocence: Poland Facing its Jewish Past".

The Holocaust wiped out centuries of shared history between Jews and non-Jewish Poles. Jews first emigrated to Poland from western Europe to escape persecution there in the Middle Ages.

"Jews have been in Poland for almost 1,000 years. Jews were part and parcel of Polish existence, of the culture, of the intellectual life, of the economic life, of the political life," said Schudrich.

'Return of Jewish memory'

No one knows exactly how many Jews there are in the population of present-day Poland, a country of 38.5 million people, said Schudrich.

"Estimates are anywhere from 20,000-50,000 and the criteria is anecdotal," he explained.

Warsaw secondary school history teacher Robert Szuchta is a pioneer in Holocaust education in Poland who has also built an international reputation.

He regularly takes his pupils around Warsaw's former Jewish quarter -- mostly razed by the Nazis during a failed revolt in 1943 -- to help them empathize with the past in what before the war was the city with the second-largest Jewish population in the world, after New York.

"Look around you," he tells the youngsters. "One resident in three in the town where you live, where you were born and go to school, spoke Yiddish. Where's that world gone?"

"I don't have any family reason for doing this," he told AFP, noting that he does not have Jewish roots. "My personal reason is that this all hurts me everywhere."

Polish-Jewish and Holocaust history are compulsory subjects through three levels of secondary schooling in Poland, taught within the main history curriculum as well as in literature, geography, civics and philosophy classes.

Szuchta said he seeks to paint an honest picture. He steers his way between those in Poland who push the idea that every Pole heroically saved a Jew from the Nazis and those abroad who push a caricatural image of Polish anti-Semites turning in their Jewish neighbors.

Schudrich has seen attendees at his Warsaw synagogue -- the only one in the capital that survived the Nazi occupation -- get younger over the years as so-called "new Jews" discover lost roots and chose to leave the mainstream in a country that is overwhelmingly Roman Catholic.

The southern city of Krakow, long an important Jewish centre, buzzes every July to a major Jewish cultural festival.

Schudrich regularly gets asked for advice on small-town projects - renovation of abandoned cemeteries, for example - and says he's noticed a subtle but crucial change in the past couple of years.

"Beforehand, wonderful people would call and they would want to save 'your Jewish cemetery', and now they want to save 'our Jewish cemetery'," he said.

"It's really the return of Jewish memory as part of the national Polish memory," he explained.