Pope Benedict celebrated his 80th birthday, Monday, lunching with cardinals and attending a concert at the Vatican. Two years after his election to the papacy, many observers have begun to assess his style, which appears very different from his predecessor. From Rome, Sabina Castelfranco takes a look at Benedict's two years as pope and who he was before being elected.

Celebrations for Pope Benedict's 80th birthday began Sunday, with a special mass in his honor in Saint Peter's Square, attended by fellow countrymen of the German Pope, wearing traditional Bavarian clothes. A Bavarian band was also in the square.

Monday, Benedict was hosting a lunch for cardinals and then, in the evening, attending a concert of Mozart and Dvorak at the Vatican. The Pope's new book on Jesus was being put on sale in bookstores, Monday, in several languages.

And, to celebrate the Pope's birthday, the Vatican post office issued commemorative stamps and Vatican employees were getting the day off and a special bonus.

The Pope was born Joseph Ratzinger, on April 16, 1927 in Marktl Am Inn, a riverside town in Bavaria. He was a quiet, thoughtful child and seemed headed for the priesthood from an early age.

Living in Germany, he experienced the totalitarian regime during World War II and was drafted into the army, but was never sent to the front.

Ratzinger was ordained into the priesthood at age 24. He began a long and successful career as a professor, teaching philosophy and theology. He became archbishop of Munich in 1977 and, later that year, he was made a cardinal.

For more than 20 years, Ratzinger served as the prefect of the powerful Congregation for the Doctrine of the Faith. He was a close friend and adviser of Pope John Paul II. Ratzinger was elected in a short conclave and took the name of Benedict, on April 19, 2005.

After his election, Pope Benedict visited Poland -- the home of his predecessor -- where he stopped to pray at the Auschwitz concentration camp. Papal spokesman Father Federico Lombardi remembers that trip as very significant.

"We have to remember, I think, the visit to Auschwitz, very impressive," he said. "The German Pope that was praying and meditating in this place of the memory of one of the most important tragedies of mankind."

Last year, Pope Benedict also visited his native Germany, where his comments at a lecture at Regensburg University caused a storm in the Islamic world.

Quoting a Byzantine emperor, Benedict said "Show me just what Mohammed brought that was new and there you will find only things evil and inhuman".

In November, Benedict traveled to Turkey where -- as Father Lombardi points out -- he tried to mend his relations with the Islamic world.

"The trip to Turkey was really very important also, because it happened after the discussion on the speech in Regensburg," he said. "That was a very important occasion, to clarify the good relationship and the attitude towards the Muslim world."

Benedict has shown he will continue to travel, like his predecessor. He has a trip scheduled to Brazil, next month. He has also shown he is very different from John Paul. He appears much more shy, although he now appears more at ease with the big crowds that gather for his masses.

Similarly to Pope John Paul, he has also continued to promote a conservative agenda on issues such as abortion, euthanasia, gay marriage and priestly celibacy. He has also made clear he wants to further dialogue between Catholics and Orthodox.