Pope Benedict XVI defended his predecessor Pius XII against Jewish critics Sunday, telling the audience at a Rome synagogue that the Vatican worked quietly to save Jews from the Nazis during World War II.Many Jews object to Benedict moving Pius toward sainthood, contending the wartime pope did not do enough to protect Jews from the Holocaust. The Vatican has maintained that Pius used behind-the-scenes diplomacy in a bid to save Jewish lives.While he did not mention Pius by name, Benedict told Jewish leaders in Rome's Great Synagogue that the Vatican "itself provided assistance, often in a hidden and discreet way."Benedict said Catholics acted courageously to save Jews even as their extermination "tragically reached as far as Rome."He spoke shortly after Jewish Community President Riccardo Pacifici criticized Pius, saying Italian Catholics worked to save Jews but the "silence" of Pius "still hurts as a failed action."Pacifici said his grandparents were killed at the Auschwitz death camp while his father was saved by Italian nuns in a Florence convent.Several prominent Jews had said they would boycott the visit, but Benedict was welcomed with warm applause as he began his visit, which he predicted would improve relations between Catholics and Jews. The synagogue sits in the Old Jewish Ghetto, the Rome neighborhood near the Tiber where for hundreds of years Jews were confined under the orders of a 16th century pope. Relations between Jews and the Vatican have at times been tense over the Vatican's sainthood efforts for Pius, who was pontiff from 1939 to 1958. Those tensions flared again after Benedict last month issued a decree hailing the "heroic virtues" of Pius, an important step before beatification, which is the last formal stage before possible sainthood.Some Jews also have been angered by Benedict's reaching out to Catholic traditionalists, including his revival of a prayer for the conversion of Jews.Another sore point is Benedict's decision to revoke the excommunication of a renegade bishop who had denied that millions of Jews died in the Holocaust. The Vatican has said it wasn't aware of the bishop's views when the excommunication was lifted.In his weekly noon appearance to pilgrims and tourists in St. Peter's Square, Benedict predicted that his visit would be a "further step on the path of harmony and friendship" between Catholics and Jews.He recalled a 1986 visit to the synagogue by Pope John Paul II, who was widely credited with dramatically improving relations with Jews. The late pontiff, who lived under Nazi occupation in his Polish homeland, where Jews were largely annihilated, affectionately referred to Jews as "our elder brothers" in faith during that groundbreaking visit.Italy's Jews are a tiny minority: about 30,000 in a predominantly Roman Catholic country of some 60 million. The neighborhood is the sentimental heart of Rome's 12,000-strong Jewish community, although many of them live elsewhere in the capital.The German-born Benedict, ahead of his meeting with Rome's Jewish community, said that "despite the problems and difficulties, you can breathe in a climate of great respect and dialogue among the believers of the two religions, testimony to how matured the relations are and to the common commitment to value that which unites us."Those unifying factors were: "faith in the one God, above all, but also safeguarding life and the family, the aspiration for social justice and peace," Benedict said. Under the leadership of John Paul and Benedict, the Vatican has been seeking common ground on such conservative agendas as traditional families while forging stronger relations with other religions, including Judaism and Islam.Before entering the synagogue, the pope was scheduled to attend a wreath-laying ceremony in front of a plaque that recalls the October 16, 1943, deportation of Jews in Rome during Nazi occupation. Another stop was planned at another memorial, which recalls the 1982 attack on the synagogue by Palestinian terrorists that killed a 2-year-old Jewish boy.Benedict has visited synagogues in Cologne, Germany, and in New York during papal pilgrimages since he became pontiff in 2005.