While the Vatican's Secretary of State praised him for a papal term marked by "joy", Catholic figures in the UK hailed the 81-year-old as a reformer who has improved perceptions.
Catholic journalist Austen Ivereigh said Francis has made the Church's governing body more open and dynamic, while placing a greater emphasis on pastoral care.
Setting out another change during the Argentinian's papacy, he added: "He's introduced a free-wheeling news conference on the papal plane coming back from his trips.
"In his first big foreign trip in July 2013, he stood in front of the world's media for an hour and a half - and they literally asked him anything they wanted - and of course that generated a huge amount of headlines.
"There's no question that he's fascinated the world, he's fascinated the news media; that's really his single greatest accomplishment, to make the Church exciting, dynamic and interesting in many ways to the world outside the Church."
Issuing his own tribute to Francis, Vatican Secretary of State Cardinal Pietro Parolin said: "I would like to say that the fundamental characteristic of this Pontificate is precisely joy, a joy that does not arise evidently from carelessness, but from the fact of knowing that one is loved by the Lord."
Paul Vallely, who wrote a biography about Pope Francis, credited the Catholic leader with encouraging dialogue within the Church and moving some decision-making powers away from the Vatican to the national churches.
He told Premier: "I think he's been an enormous success; people feel that there's a freshness to his approach.
"He's not a liberal, actually, he's quite conservative on lots of issues but he's got this new approach of putting people before doctrine."
Some critics have questioned Pope Francis' response to allegations of abuse within the Church, while others say he has failed to elevate the position of women in ministry.
Click here to listen to Premier's John Pantry and Rosie Wright speaking with Paul Vallely:
Click here to listen to Premier's Eno Adeogan speaking with Austen Ivereigh:
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