Pope Benedict XVI In Pictures

Pope Benedict XVI celebrates the Vespers and Te Deum prayers in Saint Peter's Basilica at the Vatican on December 31, 2012. He will step down for health reasons at the end of February.

The newly elected Pope Benedict XVI, previously known as German Cardinal Joseph Ratzinger, greets thousands of pilgrims from the balcony of the St. Peter's Basilica at the Vatican on April 19, 2005. Ratzinger was considered a front-runner to be elected pope.

Joseph Ratzinger (1st row, 6th from left), then 8 years old, poses with other children during their first holy communion in Aschau am Inn, Bavaria, in 1935.

Josef Ratzinger (right) with his brother Georg during their ordination in Freising, Germany, in 1951.

A photo taken in 1943 during World War II shows Joseph Ratzinger as a German Air Force assistant.

Josef Ratzinger (left), then a professor of theology, talks with Cologne's Cardinal Joseph Frings in Rome, between 1962 and 1965.

Cardinal Joseph Ratzinger meets with Russian Orthodox Archbishop Wladimir Dimitrowskij (left) during the Evangelic Academy in Tutzing, Germany, in April 1979.

Pope Benedict offers a gift as he visits the Blue Mosque in Istanbul during his historic visit to Turkey in November 2006.

Pope Benedict meets with Bosnian Muslim mufti Mustafa Ceric (left) at the Vatican's first-ever Catholic-Muslim forum in November 2008.

Pope Benedict (left) greets Russian Metropolitan Kirill during their meeting in the Vatican in May 2006.

The U.K.'s Queen Elizabeth II meets with Pope Benedict in Edinburgh, Scotland, during his historic state visit to Great Britain in September 2010.

The archbishop of Canterbury, Rowan Williams (left), greets Pope Benedict at Lambeth Palace in central London on September 17, 2010.

Former Cuban leader Fidel Castro (left) meets with Pope Benedict in Havana in March 2012.

Pope Benedict meets with Russian President Dmitry Medvedev (left) in December 2009.

Pope Benedict holds a portrait of the late Pope John Paul II during a meeting with the faithful at Wadowice, Poland, in May 2006. John Paul moved a major step closer to Roman Catholic sainthood in January 2011 when Benedict approved a decree attributing a miracle to him and announced his beatification, a step from sainthood.

Pope Benedict waves as he arrives to attend a meeting with young people in Bkerke in Harissa, near Beirut, Lebanon, on September 15, 2012.

Pope Benedict waves as he arrives to lead a solemn mass in Zagreb, Croatia, on June 5, 2011.

Pope Benedict passes through the gate of the Nazi concentration camp of Auschwitz in Poland in May 2006.

Schoolchildren wave flags showing Pope Benedict in Cameroon during his visit in March 2009.

Pope Benedict meets with Kazakh President Nursultan Nazarbaev (left) during an audience at the Vatican, in November 2009.

Mykalay, son of Belarusian President Alyaksandr Lukashenka (left), offers a book to Pope Benedict during their meeting in the Vatican in April 2009.

Pope Benedict greets the new ambassador of Iran, Ali Akbar Naseri, during their meeting in the private library in Vatican City in October 2009.

Pope Benedict greets U.S. President Barack Obama (left) during an audience in July 2009.

Pope Benedict's first tweet in different languages was sent by the pontif during his weekly general audience in Rome on December 12, 2012.