A priests swings a censer over the relics of Popes John XXIII and John Paul II during their canonisation mass on St Peter's at the Vatican on April 27, 2014. Catholics from around the world gathered in Rome on Sunday for a mass presided by Pope Francis to confer sainthood on John Paul II and John XXIII -- two influential popes who helped shape 20th century history.     AFP PHOTO / ANDREAS SOLARO        (Photo credit should read ANDREAS SOLARO/AFP/Getty Images)