Pope Benedict visited the Auschwitz concentration camp as "a son of Germany" today to meet former inmates and view an execution wall and starvation cells where some of the 1.5 million victims died.
The Pontiff (79) walked under the entry gate's infamous motto "Arbeit macht frei" (work makes you free) to tour the main Auschwitz camp, the nerve centre for a huge complex serving Adolf Hitler's "Final Solution" of wiping out European Jewry.
Pope Benedict began the last of his four days in Poland with a huge mass in Krakow, but it was marred by news of an attack on Poland's Chief Rabbi Michael Schudrich in Warsaw on Saturday by a young man shouting "Poland for the Poles!"
Rabbi Schudrich was due to pray with Benedict later today. "This incident is very nasty but let's not let it undermine the great importance of today's event," he said.
Recalling Benedict's Polish predecessor had visited the camp in 1979, Vatican spokesman Joaquin Navarro-Valls told reporters yesterday: "John Paul went to Auschwitz as a son of the Polish people and Benedict is going as the son of the German people."
After the main camp, he is visiting a nearby centre for dialogue among Poles, Germans and Jews and then pray at the Birkenau section of the camp, where Jews were led from trains straight to their deaths in gas chambers.
The symbolism of today's visit was heightened by the fact that Pope Benedict was involuntarily enrolled in the Hitler Youth organisation and then drafted into an anti-aircraft unit at the end of World War Two.
Pope Benedict, who visited Auschwitz with John Paul in 1979 and with other German bishops in 1980, has said he saw slave labourers during his short army service. The brutality of the Nazi regime helped him decide to be a priest.
Earlier today, Benedict said mass for more than 900,000 people in a field in Krakow where John Paul traditionally held huge gatherings with his countrymen before returning to Rome.
In his sermon, Pope Benedict urged Poland, which has one of the world's most active Christian communities, to "share with the other people of the world the treasure of your faith" as a fitting and lasting tribute to Pope John Paul.
Before leaving Krakow, Benedict bade farewell to a cheering crowd with the words: "See you in Rome and, if God allows it, also back in Krakow."