BIRMINGHAM, England Pope Benedict on Sunday expressed "shame and horror" over the wartime suffering caused by his German homeland and said he was moved to mark the 70th anniversary of a key air victory with Britons.
On the last day of a four-day visit to Britain that drew the biggest protest march of any of his foreign trips, the pope also beatified Cardinal John Henry Newman, one of the most prominent English converts from Anglicanism to Roman Catholicism.
The pope was seen off from the airport by Prime Minister David Cameron who said Benedict had challenged the "whole of the country to sit up and think" about issues such as social responsibility during his four-day state visit.
In his sermon to more than 50,000 people attending the open-air mass, the pope had spoken of the war and offered some personal reflections of his country's actions.
On Sunday, Britain commemorated the 70th anniversary of the Battle of Britain, the air conflict that doomed Hitler's planned invasion of Britain.
"For me as one who lived and suffered through the dark days of the Nazi regime in Germany, it is deeply moving to be here with you on this occasion, and to recall how many of your fellow citizens sacrificed their lives, courageously resisting the forces of that evil ideology," he said.
"Seventy years later, we recall with shame and horror the dreadful toll of death and destruction that war brings in its wake, and we renew our resolve to work for peace and reconciliation wherever the threat of conflict looms."
In the early 1940s, the former Joseph Ratzinger was briefly a member of the Hitler Youth when membership was compulsory. During the war, he was assigned to an anti-aircraft battery in Bavaria and then sent to Austria.
After returning to Bavaria, he deserted. At the end of World War Two, he was a U.S. prisoner of war. The pope has said that as devout Catholics, his parents rejected Nazi ideology.
Sunday was the occasion for the religious centerpiece of the trip -- putting Newman, who is venerated in both the Roman Catholic and Anglican churches, one step closer to sainthood.
Newman, who lived from 1801 to 1890 and became a Catholic in 1845, was a central figure in the Oxford Movement, which tried to move the Church of England closer to Rome.
In his homily, the pope praised Newman, a towering theologian and prolific writer whose work was very influential in 20th century Church history, for defending "the vital place of revealed religion in civil society."
One of the aims of the trip was to remind one of Europe's most secular countries of the dangers of what he has called "aggressive secularism" and "extreme atheism" that tries to shut God and religion out of public life.
On Sunday, the pope told Britain's Catholic bishops to be "generous" in applying his offer to disaffected Anglicans who want to convert to Catholicism as they feel their Church has become too liberal by ordaining woman and allowing gay bishops.
During the trip, Pope Benedict made one of his strongest apologies to victims of sexual abuse by Roman Catholic priests and met five adults who were molested as children.
The biggest demonstration held during one of his trips took place on Saturday when some 10,000 protesters marched through London carrying anti-pope banners.