Why this Pope's resignation shocked the world
When Pope Benedict XVI resigned the papacy in 2013, he became the first pontiff in nearly 600 years to step down. Watch a new episode of "Pope: The Most Powerful Man in History," Sunday at 10 p.m. ET/PT.
01:03 - Source: CNN
Pope: The Most Powerful Man in History 15 videos
Vatican City, VATICAN CITY STATE:  Pope Benedict XVI waves to the pilgrims before his weekly general audience on St-Peter's square at the Vatican, 15 June 2005.  Pope Benedict XVI has asked Cardinal Josef Glemp to celebrate in Warsaw on Sunday the beatification of two Polish priests, the Vatican announced. AFP PHOTO/ Patrick HERTZOG  (Photo credit should read PATRICK HERTZOG/AFP/Getty Images)
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UNSPECIFIED - DECEMBER 16: Pope Alexander VI (1431-1504) and those who wielded power in the empire and the papacy, detail of The Madonna of the Recommended, 1500, by Cola da Orte and Giovanni Antonio da Roma, tempera on panel. Orte, Museo Diocesano D'Arte Sacra (Diocesan Art Museum) (Photo by DeAgostini/Getty Images)
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