Look back at Pope Benedict XVI through the years.
Cardinal Joseph Ratzinger was a fixture at the Vatican long before he was pope. Here, he shows the publication of the papal encyclical Veritatis Splendor in 1993.
Ratzinger speaks at a news conference in 1999, when he was prefect of the Vatican Congregation for the Doctrine of the Faith.
Ratzinger and Pope John Paul II were close friends. Here, in 2004, Pope John Paul II greets the man who would go on to succeed him.
Ratzinger waves an incense burner around the coffin of Pope John Paul II during the funeral at the Vatican in April 2005. Ratzinger would become Pope Benedict the XVI a few weeks later.
Pope Benedict XVI waves from a balcony of St. Peter's Basilica in the Vatican after being elected by the conclave of cardinals on April 19, 2005.
Pope Benedict XVI is greeted by U.S. President George W. Bush upon his arrival at Andrews Air Force Base in 2008.
Pope Benedict XVI greets participants of the first European Meeting of University Students at the Vatican in 2009.
Pope Benedict XVI wears a police cap as he meets a former Australian police officer at the Kenthurst Study Center in Sydney in 2008.
Pope Benedict XVI waves as he arrives to lead his weekly audience in Saint Peter's Square at the Vatican in 2009.
Pope Benedict XVI celebrates the First Vespers and Te Deum prayers in Saint Peter's Basilica at the Vatican in 2009.
Pope Benedict XVI wears a Saturno hat as he leaves at the end of his Wednesday general audience in Saint Peter's Square at the Vatican in 2009.
Pope Benedict XVI visits the Western Wall, Judaism's holiest prayer site, in Jerusalem's Old City in 2009. Pope Benedict visited holy sites in Jerusalem at the heart of the Israeli-Palestinian conflict as part of a pilgrimage beset by Jewish disappointment over his remarks on the Holocaust.
President Barack Obama and first lady Michelle Obama meet with Pope Benedict XVI at the Vatican in July 2009.
Pope Benedict XVI arrives to lead a special audience with the Italian civil protection department at the Vatican in 2010.
Pope Benedict XVI replaces his zucchetto as he stands with Britain's Queen Elizabeth at the Palace of Holyroodhouse in Edinburgh, Scotland, in 2010.
Pope Benedict XVI nods off during a mass at the Granaries in Floriana in April 2010.
Pope Benedict XVI waves to the crowd gathered below in Saint Peter's square during his weekly Angelus blessing at the Vatican in 2010.
Pope Benedict XVI waves as he arrives to lead a special audience with members of Italian Caritas in Saint Peter's Basilica at the Vatican in November 2011.
Pope Benedict XVI attends a Mass celebrating the 200th anniversary of the independence of Latin American countries at St. Peter's Basilica in December 2011.
Pope Benedict XVI meets Former Cuban leader Fidel Castro in Havana in March 2012.
Pope Benedict XVI waves as he arrives at Saint Peter’s Square in 2012.
Pope Benedict XVI pets a young lion as he leads a special audience for circus artists and musical acts at the Vatican in December 2012.
Pope Benedict XVI posts his first tweet using an iPad tablet at the Vatican in December 2012.
Pope Benedict XVI leaves at the end of a mass at the St. Peter Basilica in Vatican Feb. 9, just a few days before announcing he would step down as head of the Catholic Church on Feb. 28, 2013.
Pope Benedict XVI holds his last general audience in St. Peter's Square at the Vatican on Feb. 27, 2013, speaking before a crowd of tens of thousands and blessing several babies in the crowd.
Pope Benedict XVI greets members of the Cardinals following his last meeting with the group before leaving the Vatican on Feb. 28, 2013.
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