Cardinal George Pell seems to have been given a remarkable level of authority in his new post at the Vatican, but he will face considerable challenges settling in and asserting his role.

Pope Francis has created an entirely new economic leadership position and a new Secretariat in the Vatican.

Cardinal Pell, the Archbishop of Sydney, will move to Rome by the end of March to serve as Cardinal-Prefect and head up the newly-announced Secretariat for the Economy.

This is the first significant appointment in the Pope's promised reform of the Vatican bureaucracy, which he once referred to as "the leprosy of the papacy".

The new body will oversee the $US308 million annual budget of the small Vatican state and its 2,800-odd employees. It remains to be determined how much influence the Secretariat will have over the estimated $US8 billion in assets estimated to be held by the Vatican bank.

As a sort of "Chancellor of the Exchequer", Cardinal Pell becomes the exceptional 10th of what were historically only nine Cardinal-Prefects.

These powerful 10 Cardinal-Prefects head the major departments of the Vatican's bureaucracy; the Curia. The move means Cardinal Pell could well become the third most powerful Cardinal in the Vatican.

Even the Cardinal Secretary of State, second in charge to the Pope, will face financial scrutiny from the new Prefect.

The appointment of 72-year-old Cardinal Pell to oversee and overhaul church finances may yet prove a master-stroke in Pope Francis's program of church reform.

Cardinal Pell is a doctrinal conservative. But he is tough. He is determined. His clear-minded take-no-prisoners approach may be just what is needed in dealing with the Byzantine bureaucracy of a huge international church. Out with the old, in with the new. Reform is under way.

Cardinal Pell to face challenges in Vatican role

Though a frequent-flyer to the Vatican, and serving on numerous committees, Cardinal Pell will be the new boy on the residential Vatican bureaucracy block.

All sections of the Vatican Curia will be answerable to the new Secretariat and Cardinal Pell for financial and administrative matters.

His elevation means he can look into the financial workings of all the other Cardinal-Prefects of Rome.

The Pope has said what he wants Cardinal Pell to do, but he yet has to try to do it. And the Curia is historically notorious for obstructing reform.

Comedy series Yes Minister has nothing on the Roman Curia. Cardinal Pell is tasked with achieving real and significant reform. He will need to be "courageous". Fortunately, he is not known for shyness.

The Vatileaks scandal of 2012 revealed allegations of money-laundering. Vatileaks added to the stench of the Vatican bank saga going back to the Banco Ambrosiano scandal, the mafia and Roberto Calvi hanging dead under Blackfriars Bridge in London.

The Vatican bank (The Institute for Religious Works) remains a private entity regulated by the Monetary Agreement between the European Union and the Vatican City state.

The bank has about 33,000 accounts, a distribution network in more than 100 countries, and an estimated $US8 billion in assets. But it is understood its activities will also come under the purview of Cardinal Pell.

The letter (Motu Proprio) appointing the Cardinal-Prefect says explicitly he will be "supervising the structures and the administrative and financial activities of ... the institutions connected to the Holy See, and of Vatican City state".

Read Cardinal Pell's new job description.

In leading the church charity Caritas, the vast Archdiocese of Melbourne and the enormous Archdiocese of Sydney, the cardinal has consistently surrounded himself with financial experts.

In Sydney, his achievements include reforming Archdiocesan finances, the establishment of a second Catholic University and the first Catholic medical school, Rome's Domus Australia, the expansion of CatholicCare, plus extensive refurbishment and endowment of his Cathedral and its renowned choir.

Before the Cardinal commences in this newly created position in the Vatican, he will be required to give evidence to the Royal Commission into Institutional Responses to Child Sexual Abuse, sometime between March 10 and 18. He is expected to leave shortly after.

Sorry, this video has expired Cardinal George Pell appointed to Vatican ( Rebecca Armitage )

The ABC can confirm, following discussion with Katrina Lee, director of Catholic Communications Archdiocese of Sydney, that an interim administrator will replace the Cardinal within the Archdiocese of Sydney - probably within the next 48 hours.

As to a successor to the Archdiocese of Sydney, clerical pundits favour two front-runner names.

Mark Coleridge, 66, the Archbishop of Brisbane with long experience in the Vatican (though he has not been long Brisbane's Archbishop), and former lawyer Anthony Fisher, 53, currently Bishop of Parramatta..

While Australian Cardinal Edward Cassidy previously served as president of the Pontifical Council for Promoting Christian Unity, Cardinal-Prefect Pell now becomes the most senior Australian ever to have served in the world-wide Catholic church.

With three living Australian cardinals (including also Cardinal Edward Clancy), the question of the next Australian Cardinal's red hat could well remain open until 2021, when Cardinal Pell turns 80 and loses the right to vote in papal conclaves.

Noel Debien is a member of the ABC Radio Religion and ethics Unit. He produces RN’s Religion and Ethics Report (Wed 5.30pm, Thurs 5.30am) and NLR‘s Sunday Nights (Sun 10pm- Mon 2am). He is currently presenting the Religion and Ethics Report while Andrew West is Seconded to Late Night Live.