We are now seeing smoke emerge from the Sistine Chapel’s chimney – and it's black.

This means the cardinals have not been able to chose a new pontiff - which requires a two-thirds majority. There will be more rounds of voting tomorrow, and going forward if no decision is made.

As a reminder, the cardinals in the chapel have no communication with the outside world until a new pope is elected.

Image source, Reuters

Despite night starting to fall in the Vatican, the crowds waiting to see smoke from the Sistine Chapel chimney are still going strong.

The latest estimate from the police is that about 30,000 people are currently in St Peter's Square.

Image source, Reuters

Image source, Reuters

Tina Beattie, former professor of Catholic Studies at the University of Roehampton, has just been telling the BBC News channel that "everyone's a bit bewildered" as to why the first vote round is taking so long.

She says she's also surprised that we're into the third hour of voting, but she suspects it's because "the homily went on a bit long or something mundane like that".

She also adds that a lot of the cardinals in the Sistine Chapel are new to the process, so "it may well be it doesn't go quite as smoothly" as it would if they were all old hands.

"We shouldn't underestimate how challenging" the process might be for newer cardinals, adds Beattie.

We've been watching the Sistine Chapel chimney for about two hours now and we're still waiting for the smoke that signals whether cardinals have decided on a new pope.

If you're just joining - the conclave has started, with cardinals currently locked inside the Sistine Chapel for the secretive voting process.

If we see black smoke tonight, voting will commence again in the morning. White would mean a new pope has been elected.

This conclave is different from others gone by because the late Pope Francis appointed many younger cardinals from different parts of the world.

In short, it means this conclave is larger and has a more global perspective.

Laura Gozzi
Reporting from the Vatican

There's intermittent clapping, almost as if people in the square are willing the smoke to come out of the chimney of the Sistine Chapel.

Laura Gozzi
Reporting from the Vatican

Image source, Reuters

St Peter's square is extremely busy, with long queues at the security points under the colonnades.

There are thousands of people here - black-frocked priests, pilgrims and many, many tourists.

All are standing facing the right of the square towards the chimney that should billow out black or white smoke imminently.

Nobody is really expecting it to be white at this stage - the first vote taken by the cardinals is usually a way for them to see which names may be serious contenders.

A number of them will only get a handful of votes and from tomorrow consensus will start to coalesce around the more credible candidates.

But still, the Catholic Church's long history means nothing is quite unprecedented. So, really, you never know.

Carine Torbey
BBC World Service, in Vatican City

The crowd’s size at the Vatican has grown exponentially in the last hour. Everyone is waiting for the outcome of the first ballot.

We are standing among the crowds and people are coming to us to ask about the exact location of the Sistine Chapel and the roof they should keep an eye on.

Moments of suspense as history unfolds in front of hundreds of thousands of pairs of eyes, all fixed on a chimney.

Image source, Reuters

Scarlett Barter
BBC World Service, in Vatican City

As the sun starts to go behind St Peter Basilica the square is getting busy. There is an anxious excitement. Everyone’s eyes and phones fixed on the chimney.

To the outside world, the only information about how the conclave is progressing is smoke from the chapel's chimney when ballot papers are burned after each round of voting. Black smoke signals failure.

White smoke means a new Pope has been chosen. The new pontiff normally appears on the balcony overlooking St Peter's Square within an hour of his selection.

The senior cardinal confirms the decision with the words "Habemus Papam" - Latin for "we have a Pope" - and introduces the new pontiff by his chosen papal name, which may not be his original given name.

For example, Pope Francis was born Jorge Mario Bergoglio, but chose his papal name to honour St Francis of Assisi.

Alicia Hernández
BBC News Mundo, in Vatican City

Image source, EPA

Many believers, tourists, curious onlookers, and press from around the world are gathered at this hour in St Peter's Square awaiting the first smoke.

A group of Italian civil protection workers ask me, curious, to zoom in with my camera on the chimney where the white or black smoke will be visible - depending on whether a new pope has been elected or not.

"We know the new pope won't be known today; we're anxiously awaiting for him, but we know it won't happen yet," one of them tells me.

Another one says his favourite is Italian cardinal Pietro Parolin: "I want it to be Parolin. He's been a very good cardinal."

The third one replies: "I prefer Omella, the one from your country," referring to Juan José Omella, cardinal of Spain.

"But for now, we have to wait," they tell me.

Image source, Getty Images

Here is a selection of names being mentioned as Francis's potential successor:

Peter Kodwo Appiah Turkson was the first Ghanaian to be made a cardinal, back in 2003 under Pope John Paul II, and was made favourite by bookmakers ahead of voting in 2013 when Pope Francis was instead selected.

Softly spoken Italian Cardinal Pietro Parolin was the Vatican's secretary of state under Pope Francis – making him the Pope's chief adviser. The secretary of state also heads the Roman Curia, the Church's central administration.

Could Cardinal Luis Antonio Gokim Tagle become the first Asian Pope? The Church is massively influential in the Philippines, where about 80% of the population is Catholic and the country currently has a record five members of the College of Cardinals – which could make for a significant lobbying faction.

It's very possible the next pope could be from Africa, where the Catholic Church continues to add millions of members. Cardinal Fridolin Ambongo Besungu is a leading candidate, hailing from the Democratic Republic of Congo (DRC), where he has been Archbishop of Kinshasa for seven years.

You can read more on the emerging candidates in our profile of the leading contenders.

Image source, Reuters

From now on, the cardinals cannot have any communication with the outside world until a new pope is elected.

There will only be one round of voting this afternoon, but if a decision is not made, the cardinals vote up to four times every day afterwards.

Because a new pope requires a two-thirds majority, the process can take some time, although the last two conclaves concluded by the end of day two.

To cast their vote, each cardinal casts their vote on a card that says in Latin "I elect as Supreme Pontiff" alongside the name of their chosen candidate.

They walk in order of their seniority to place their cards inside the large silver and gilded urn.

Read more on how the next pope is chosen here.

The papal master of ceremonies has now closed the doors and the conclave has begun.

The word for conclave comes from the Latin for "cum clave", or "locked with key".

The Vatican cameras have departed from the chapel.

The cardinals have now finished swearing their oaths.

And the Master of Pontifical Liturgical Celebrations, Diego Ravelli, has just announced "extra omnes", essentially "everyone out".

Those not taking part in the conclave will now leave.

Carine Torbey
Reporting from the Vatican

I spoke to a group of five people from the Philippines.

"We will stay here to see the white smoke. If it doesn't happen today, then we will come back tomorrow," says Maria Lourdes Carbonell.

"It's unforgettable," she says.

"We were hoping to see Pope Francis. But now we are here, and we will see who will be the next pope."

I asked whether they are hoping for their compatriot, Cardinal Luis Antonio Tagle - to become pope.

"We have no preference. We will be happy with whoever the Holy Spirit inspires the cardinals to vote for," she says.

Carine Torbey
Reporting from Vatican City

"It's a historic event, and it's great to feel part of history. And tell your children: we were there, we saw that."

This is how Rita and her husband Roger Marc described their feelings as they stood among tens of thousands in Saint Peter's Square, following the rituals of the start of the conclave on big screens.

They live in London and had booked their Rome holiday months ago.

Roger tells me it is "intriguing" to see all the media organisations set up to cover the event, and the crowds taking pictures.

Image source, Pool

We're still watching the cardinals swearing their oaths to abide by the rules of the conclave.

There are 133 cardinals, and many at still queuing up to take the oath.

All vow to observe "absolute and perpetual secrecy".

Although they come from the across the world, they are speaking in Latin - the official language of the Roman Catholic Church.

Laura Gozzi
Reporting from Vatican City

Lots of people are gathered around the giant screens near St Peter's Basilica watching the cardinals file in, their oaths echoing out from loudspeakers.

Daniel Wainwright and Jess Carr
BBC News Visual Journalism Team

What do we know about the men who will shortly begin choosing a new pope?

We can’t know how the cardinals will vote, but there are interesting insights about their age and background we’ve been exploring and visualising.

This chart shows, for example, how the world's 252 cardinals range in age from 45-year-old Cardinal Mykola Bychok to 99-year-old Cardinal Angelo Acerbi.

Only 133 cardinals - all under the cut off age of 80 - will vote.

Two cardinals aren’t taking part because of ill health.

Another, Cardinal Giovanni Angelo Becciu, 76, has also withdrawn, according to Vatican News, external. In 2023, he was convicted of financial crimes by a Vatican court, a ruling he is appealing.

Cardinals from Europe make up the biggest group of those with a vote and eight-in-10 of all the voting cardinals were appointed by Francis.

Our interactive article lets you explore this in more detail, including how Pope Francis has created a more global conclave to find his successor than the one that appointed him.

Image source, Pool

We're now seeing the cardinals taking the solemn oath.

Within it, they are promising to keep secret all matters related to the election, and promising that whichever of them should be elected pope will faithfully carry out the petrine office of pastor of the universal church.