Pope Benedict XVI (37 images)

Pope Benedict XVI drives past the White House after participating in an official welcoming ceremony with President George W. Bush on the South Lawn of the White House on April 16, 2008. This is the Pope's first visit to the United States and only the second visit in history by a Pope to the White House. (UPI Photo/Kevin Dietsch)

Pope Benedict XVI and U.S. President George W. Bush listen to music during an official welcoming ceremony on the South Lawn of the White House in Washington on April 16, 2008. (UPI Photo/Aude Guerrucci/Pool)

Pope Benedict XVI shakes hands with U.S. President George W. Bush during an official welcoming ceremony on the South Lawn of the White House in Washington on April 16, 2008. This is the Pope's first visit to the United States and only the second visit in history by a Pope to the White House. (UPI Photo/Roger L. Wollenberg)

Pope Benedict XVI sits with U.S. President George W. Bush during a welcoming ceremony on the South Lawn of the White House in Washington, on April 16, 2008. The Pope, who is celebrating his 81st birthday today, is on a six day visit to the U.S. (UPI Photo/Shawn Thew/POOL)