About a week after Benedict XVI’s papacy ended in late February 2013, the Christian world stunned by the first resignation of a sitting pope in six centuries, cardinals from the four corners of the world began gathering in Rome to elect his successor. Vivian Lee explores what happened next.

One hundred and fifteen so-called ‘Princes of the Church’ – the scarlet they wear, a symbol of their willingness to die for their faith – would choose Benedict's successor by secret ballot in a papal conclave an election for a pope.

Over a week, they met over lunch, dinner, sometimes just coffee.

Some needed to get to know the others better. All needed to discuss the challenges the church faced.

The Sistine Chapel was prepared with special seating and a dais, as well as the two stoves that would funnel white and black smoke to the roof at the end of each voting day to signal whether a new pope had been elected. 

All this had been done eight years before, when Cardinal Joseph Ratzinger of Germany became pope.

But as National Catholic Reporter editor Dennis Coday described it then, things were different this time.

"There was a feeling, kind of a surge toward consensus of just a few candidates.

And there was a strong feeling even early on, even before the conclave, that it would go to Joseph Ratzinger," he said. "But what they're telling us, people who have been through this before, they're saying they're not feeling that."

Voting began on March 12.

The holiest day on the Christian calendar, Easter Sunday, was 19 days away.

Not that anyone felt pressure, the cardinals said, but it would be nice to have the new leader installed by that day.

Not since the early 1800s had any papal conclave lasted more than four days.

The longest papal conclave ever was back in the 13th century, when cardinals took three years to pick Pope Clement IV’s successor.

At the start of this conclave, cardinals prayed in St. Peter's Basilica to the Holy Spirit for guidance.

They had lunch, professed allegiance to the next pope, and then locked themselves inside the Sistine Chapel. This tradition dates back centuries, when spying, assassinations, and bribery to sway the vote were serious threats.  

Then, more than two hours later, black smoke signaled no decision.

But that first round of voting helped clear the fog a bit. 

"For the first time, the cardinals really know how much support each candidate really has because they actually had a vote," said Father Tom Reese of the National Catholic Reporter at the time. "Everything else has been rumor. Tomorrow when they come in and vote, the key thing will be, do their votes increase? "

Rumors had kept the media busy for days. There were no obvious frontrunners. So, why not an American pope this time, some asked.

The Catholic Church in the U.S., while losing membership, did have the most experience handling cases of alleged sexual abuse by priests.

Similar cases were surfacing across Europe.

Cardinal Timothy Dolan of New York, respected for his ease with the media, and his pastoral joy, was called a dark horse candidate. So was Cardinal Sean O'Malley of Boston, a Capuchin monk who was straightforward and sincere.

But the Church was strongest and growing among Latinos, so maybe the world was ready for a South American pope.

And eventually, a decision was made. "Habemus Papam!" people cheered as white smoke speared above the roof of the Sistine Chapel.

After five rounds of voting, a pope had been selected.

Cardinal Jorge Mario Bergoglio, the 76-year-old Archbishop of Buenos Aires, a Spanish-speaking Jesuit far removed from Vatican intrigue, first signaled things would be different going forward with his papal name.

"That was kind of the first surprise. First pope to choose the name of Francis. You could see almost an ‘aw shucks’ attitude, almost a child-like simplicity, almost like a refreshing awkwardness that he’s, oh, now what do I do? Where do I go? I can remember when he went into the room and put on his new white cassock, you see. And when he came out we, of course, all applauded, and he kind of just looked at us and shrugged like look at me, I never expected this," said Cardinal Timothy Dolan.

Francis greeted the faithful from the central balcony by calling them brothers and sisters.

He asked them to pray for his predecessor and for him.

He sounded a little shy.

"You know that I was in the conclave. It was to give a bishop of Rome. It seems that my brother cardinals went to choose him from the end of the world. But we are here. I thank you for the hospitality for greeting me," he said.

He kept the iron cross around his neck, refusing to trade it in for the traditional gold one worn by most popes. He wore a simple white cassock, foregoing the fur and gold trimmed mozzetta cape reserved for his post.  And he did something else after the balcony address that the cardinals who elected him noted.

"We left that night after he had greeted the throng in St. Peter’s Square, we saw the buses to take us back, but we also saw the papal limousine, with the motor escort ready for him. And he’s walking back with us and says, ‘Ah, no, I’ll go back with my fellow cardinals.’ And he got back on the bus," Dolan said.

Other examples of his humble nature are now part of the lore that surrounds Francis. He lives in an apartment for guests in Vatican City, not the Apostolic Palace where his predecessors lived. He's chauffeured in a Ford Focus, not a luxury car. The opulence that's come to be associated with the papacy is something Francis shrugs off.

He's got other things to deal with.

"When Francis was elected in March 2013, the church was in a terrible state. An incredible crisis, scandals at the Vatican, the Roman Curia, the papal bureaucracy was completely dysfunctional, the reputation of the church was down. It was a mess," said journalist and author David Gibson, who writes for Religion News Service.

Some clergy likened the battered church to the wounded Jesus before he was crucified.

But Francis has now instituted international banking standards at the Vatican Bank, a first.

He created a commission of clergy and lay people and a Vatican tribunal to investigate and judge bishops who aided sexual abusers in the church, another first.

He is re-populating the Vatican administration with cardinals from poor nations, not rich ones.

Some say these changes have sown resentment within the Vatican.

"Have we passed the point of no return? If Francis dies tomorrow, whatever, are his changes irreversible? To some degree, yes. Is the Francis revolution finished? Not by any stretch. Will it continue? That’s the big question. I don’t think anybody has a good answer," Gibson said. "But he’s got to appoint more cardinals. Men who share his vision, so that when he leaves, and they gather in the Sistine Chapel for the conclave, they’ll be looking for  someone – not a Francis clone – but who shares that vision and carries it forward."

Polls have shown he has raised the image of the church among the faithful and secular.

More importantly for the clergy, some Catholics are looking over their shoulder at the church they turned away from.

"See a bit of an uptick in those attending Sunday mass, we see people returning to confession, and people saying, ‘You know, Father, it’s been a long time.’ The inspiration of Pope Francis has moved to a conversion of heart here, even an increase in collections," Dolan said. "So whatever it is, this so-called Francis effect, is a gift, and even though I’m still waiting to see more scholarly or scientific evidence to back it up, we pastors know that something good is going through the church, thanks to him."

Francis himself once said he doesn't think he'll be pope for long – he reportedly wants to live out his days in his beloved Argentina.

However long Catholics can claim him as leader, many say so far that his impact has been undeniable.