Pope Francis once likened sorting out the Vatican's tangled accounts to "cleaning the Sphinx of Egypt with a toothbrush".
By dismissing a close aide linked to a murky London property deal in a move described as "the most significant firing of his papacy", analysts say Francis has deployed a pressure washer to alleged in-house financial impropriety.
Last week, the 83-year-old pontiff forced the resignation of Italian Cardinal Angelo Becciu, a prominent member of the church hierarchy and close adviser to the prelate.
The former No 2 at the Vatican's Secretariat of State, which manages the church's vast donations, has been accused of syphoning off funds destined for the poor to family members -- a charge he denies.
Becciu has been linked in particular to a controversial luxury property investment deal in London, with at least some of the money used reportedly coming from the annual Peter's Pence collection for the poor.
It is not the only financial scandal to have dogged the Vatican in recent years: in 2017, the ex-head of a Vatican-run hospital was convicted of funnelling a fortune from a foundation to renovate a cardinal's apartment.
And the Vatican bank, known as the IOR, was for decades embroiled in numerous controversies, with one of its former presidents ordered to stand trial on charges of embezzlement and money laundering in 2018.
But Francis has upped the speed of his reforms recently, suggesting he is "losing patience" with moral persuasion and "is more inclined to make heads roll," said John Allen, Vatican expert for the Cruxnow.com religious news site.
"'Accountability,' in the full American sense of the word, is finally crossing the Tiber in the Pope Francis era," he said, describing it as "by far the most significant firing" of the pontiff's era.
The surprise decision to also strip Becciu of the rights associated with being a cardinal -- a very rare punishment -- was a clear signal ahead of an inspection Wednesday by Moneyval, the Council of Europe's anti-money-laundering monitoring body.
- Painstaking work -
Vatican expert Marco Politi described the pope's action on Becciu as "a Napoleonic gesture".
"With his iron fist, Francis wanted to show that sanctuaries do not exist, that no fiefdom is safe," he told AFP.
Soon after being elected leader of the world's 1.3 billion Catholics in 2013, Jorge Bergoglio vowed to continue efforts to fight corruption begun by his predecessor, Benedict XVI.
Around 5,000 suspect accounts were closed at the Vatican bank under Francis.
And in a bid to streamline the Holy See's administration, its finances are to be condensed into a single organisation, the Administration of the Patrimony of the Apostolic See (APSA), which currently manages thousands of Vatican properties.
The Italian bishop at the head of APSA, Nunzio Galantino, said that in future all operations must be "transparent" and "traceable".
"If the pope asks me 'Have we got the money to pay the salaries?', I must be able to give him a precise answer," Galantino told Corriere della Sera on Tuesday.
Each entity -- including the Secretariat of State -- will make a budget request, which will be decided by a Spanish Jesuit priest who took over the Secretariat for Economy in January and will oversee the funds centralised by APSA.
Exerting more centralised control has angered some rivals, said Honduran Cardinal Oscar Maradiaga, coordinator of a group of six cardinals advising the pope on his economic reforms.
The biggest obstacles have been "internal enemies," he told La Stampa daily.
"Because when you delve into the funds and the department administrations you find things that aren't right, and this provokes very severe reactions," Maradiaga said.
- A lonely pope -
Various Vatican factions have remained silent as the pope has striven to shake up financial oversight, according to Vatican writer and journalist Politi.
Those include conservatives "happy that there are scandals" brought to light through Francis' actions, and therefore which damage his papacy, in their view.
But even the reformist front has not defended Francis' shakeup.
"In this earthquake you can see the loneliness of Francis," Politi said.
One message of support came from Australian Cardinal George Pell, who was due to arrive in Rome for the first time in three years after being acquitted in April in Australia of child sexual abuse charges.
"I hope that the cleaning of the stables will continue in the Vatican," Pell said.
Pell in 2015 hired external auditors to oversee the Vatican books, but his efforts were thwarted by Becciu, who cancelled the $3-million contract with PricewaterhouseCoopers.
A Vatican source told AFP the Vatican judiciary will bring charges soon against Becciu, and six other Vatican employees.