Poland is preparing to mark one of the darkest episodes of the Holocaust, when the country's Nazi German occupiers launched an operation to kill the population of the Jewish ghetto they created in Warsaw.
Sunday's solemn tribute to the victims of the mass deportations that began on July 22, 1942, will be capped by a memorial concert in what was once the Polish capital's Jewish quarter.
On that date 70 years ago, after almost three years of brutal control the Nazis began deporting the ghetto dwellers to Treblinka, a death camp they set up 100 kilometres (60 miles) northeast of the capital.
A total of 260,000 members of Warsaw's Jewish population -- at the time the largest in the world outside New York -- were to perish there.
Commemoration organisers will in particular honour the memory of youngsters who died, with a march retracing the steps of pediatrician and child-rights campaigner Janusz Korczak and the 200 young charges from his ghetto orphanag.
"We want to remember the figure of Korczak, and the children who were the majority, and easiest, victims," Pawel Spiewak, head of Poland's Jewish Historical Institute, told AFP, underling than just 500 children survived the ghetto.
On July 22 the Nazis ordered ghetto dwellers without special work permits to assemble at the "Umschlagplatz" rail-head, on pain of being shot.
"In the space of three months, 260,000 people were deported and killed. That was a quarter of the population of Warsaw. Along with them, an entire culture disappeared from the city forever," said Spiewak.
Pre-war Poland was a Jewish heartland, with a centuries-old community numbering some 3.2 million, or around 10 percent of the country's population.
Polish Jews made up half of the Holocaust's six million victims.
After invading in September 1939, Nazi Germany moved to isolate Jews in ghettos before beginning systematic killing.
Warsaw's 400,000-strong Jewish community was the largest. The ghetto's population rose to half a million as the Nazis forced in Jews from other towns.
In November 1940 they walled off a four-square-kilometre (1.5 square miles) area of the city, mostly around its traditional Jewish quarter.
About 100,000 were to die inside from starvation, disease or summary execution, with exploitation in the Nazis' war economy one of the few ways to survive.
The July 22 order was part of Operation Reinhardt, launched late in 1941.
A total of two million Jews died in that two-year campaign to empty occupied Poland's ghettos, in Treblinka as well as Belzec, Sobibor and Majdanek.
When the three-month Warsaw operation was complete, the ghetto was reduced
to a rump of less than one square kilometre (half a square mile), with a registered 35,000 Jews and 25,000 others in hiding.
On April 19, 1943, as the Germans moved to kill the survivors, hundreds of poorly-armed Jewish paramilitaries rose up in Europe's first urban anti-Nazi revolt.
They held out for three weeks.
Around 7,000 Jews died in the revolt, most of them burned alive, and more than 50,000 were deported. Estimated Nazi losses were 300, dead and injured combined.
Ghetto survivors fought in the Warsaw uprising which began on August 1, 1944 as the Polish underground tried to seize the city from the Nazis before the Soviet army arrived.
That failed, 63-day revolt and the Germans' brutal response cost the lives of 200,000 civilians and fighters, and led to Warsaw's near-total destruction by the Nazis, who then retreated before the Soviets arrived in January 1945.
Sunday will see the first official ceremonies marking the start of the deportations.
"To date, July 22 has not figured on Warsaw's calendar," said Spiewak.
Under the five-decade communist regime it was overshadowed by celebrations of the July 22, 1944, creation of the first pro-Soviet government, with the main ghetto memorial held on April 19.