The Pope Francis phenomenon
21 December 2013 Last updated at 00:03 GMT
Born in Argentina, Pope Francis is the first Latin American - and the first Jesuit - to lead the Roman Catholic Church.
Earlier this month, he was named Person of the Year by Time magazine, with the publication saying the Pope had pulled "the papacy out of the palace and into the streets".
It has been an extraordinary year for the Catholic Church under the leadership of Pope Francis.
In just nine months since taking over from Pope Benedict he has vigorously set about modernising the Church.
Paul Vallely, biographer of Pope Francis, has been to Rome for BBC Newsnight to look at the Francis phenomenon.