Children dressed in traditional Bavarian costumes dance for Pope Benedict XVI on the occasion of the Pontiff's 85th birthday celebrations in the Clementine hall at the Vatican, Monday, April 16, 2012. (AP Photo/Gregorio Borgia, Pool) In this picture made available by the Vatican newspaper Osservatore Romano, Pope Benedict XVI leads a mass at the Vatican, Monday, April 16, 2012. The Pontiff celebrated a very Bavarian birthday Monday, marking his 85 years with his brother, German bishops and a musical band from his native land. Benedict began the day with a Mass in which he alluded to his own mortality, saying he would carry on his final years knowing that God was watching over him. (AP Photo/Osservatore Romano) Children dressed in traditional Bavarian costumes dance for Pope Benedict XVI on the occasion of the Pontiff's 85th birthday celebrations in the Clementine hall at the Vatican, Monday, April 16, 2012. (AP Photo/Gregorio Borgia, Pool) Believers walk from the house where pope Benedict XVI was born to the church for prayers in Marktl, southern Germany, early Monday, April 16, 2012, to celebrate the pope's 85th birthday. The believers gathered at 4:15 in the morning, the exact time of the pontiff's birth. (AP Photo/dapd, Lukas Barth) Believers and clerics stand around the baptismal font of pope Benedict XVI during prayers at the church in Marktl, southern Germany, early Monday, April 16, 2012, to celebrate the pope's 85th birthday. The believers gathered at 4:15 in the morning, the exact time of the pontiff's birth. (AP Photo/dapd, Lukas Barth)