Revealed: How voting for new pope unfolded - and the internal battle that cancelled out two contenders

Conclaves are famously unpredictable affairs – and once again the election of Cardinal Robert Francis Prevost as the new pope caught many by surprise.

The newly elected Pope Leo XIV won the consensus of the 133 cardinal electors after only four ballots - a fast process for a diverse college of cardinals. Though his name had circulated among some Vatican watchers, other cardinals had emerged as clear front-runners, including Pietro Parolin - the Vatican's number two who would have been the first Italian in almost 50 years to become pontiff - or Luis Tagle, a Filipino cardinal looking to become the first Asian pope.

Instead, it was the first North American to win the highly secretive process. So, what went on behind the closed doors of the Sistine Chapel? Until Thursday lunchtime, Cardinal Parolin was ahead, gathering between 45 and 55 votes, sources say.

A substantial number, but well short of the 89 votes he needed for a two-thirds majority. At this point, Cardinal Prevost had between 34 and 44 votes.

But as the Italian struggled to grow his support during the first three rounds of voting, he stepped down from the race, endorsing Prevost instead, Sky News understands. Read more:Who is Pope Leo XIV?List of demands in new pope's in-trayHow does new pope compare to his predecessors? An internal battle between Luis Tagle and Pablo Virgilio David - both cardinals hailing from Asia - cancelled out both of their chances.

And a contender from Africa - the most conservative sector of the church - was never likely for a conclave where the overwhelming majority of cardinals had been appointed by Francis, a progressive pontiff, sources say. An American pope has long been seen as highly improbable, given the geopolitical power of the US.

But Cardinal Prevost was able to draw from across the groups making up the electors: moderate US cardinals, South American cardinals and many European cardinals all coalesced around him. Italian newspaper La Repubblica said Prevost "certainly attracted cross-party preferences, both ideologically and geographically".

"In the conclave he was the least American of Americans: Born in Chicago, he lived 20 years in Peru," the newspaper said. It added: "As a man used to teamwork, Prevost appeared to many as the right man to make the papacy evolve into a more collegial form.".