Image source, Vatican Media / EPA

We're still seeing images from inside the Sistine Chapel.

Once they are closed inside the chapel, the cardinals must have no communication with the outside world until a new pope is elected.

There is only one round of voting this afternoon, but the cardinals vote up to four times every day afterwards until a new pope is chosen, with a two-thirds majority required.

Each cardinal casts his vote on a simple card that says, in Latin: "I elect as Supreme Pontiff" to which they add the name of their chosen candidate.

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

Image source, Pool

The cardinals are now in the Sistine Chapel, under the famous frescoes painted by Michelangelo.

Each cardinal has bowed at the altar inside and taken their seat.

Once the doors have been shut and the words "extra omnes" have been uttered, the conclave will have officially begun.

Cardinals will hold a first secret ballot this evening.

We can bring you images now of the cardinals making their way to the Sistine Chapel - where the conclave will shortly start.

Image source, Pool

Image source, Pool

Image source, Pool

Image source, Pool

Image source, Pool

We are now seeing the start of the cardinals' procession from the Pauline Chapel to the Sistine Chapel.

It is in the famous Sistine Chapel that the election of the new pope will take place – and have done so since the 15th Century.

The last conclave, in 2013, elected Pope Francis after just five rounds of voting, making it one of the quickest decisions in modern times. In earlier centuries disagreements sometimes caused conclaves to stretch on for months.

After the voting has taken place the faithful gathered in St Peter’s Square - and those watching around the world - will wait for the moment smoke comes out of the Sistine Chapel chimney.

Black smoke means more voting will take place tomorrow. White means we have a new pope.

Remember you can follow along by clicking the Watch live button at the top of the page.

Maryam Moshiri
Chief Presenter, BBC News

Image source, Getty Images

Well, the longest conclave ever went on from 1268 to 1271 - when Pope Gregory X was elected after an almost three-year process.

The shortest conclave lasted just 10 hours and ended with the election of Pope Julius II in 1503.

In modern times, the last few have all been done within two or three days.

The first vote happens this evening and if there is no decision then, the Cardinals will come back and repeat the process tomorrow.

As we've mentioned, the conclave will soon commence. Here is a quick guide to the major events we are still watching out for:

• Around 16:30 local time (15:30 BST) the cardinals will start a procession from the Pauline Chapel to the Sistine Chapel
• At around 17:30 (16:30 BST) everyone but the electors must leave the Sistine Chapel - the moment "extra omnes" is pronounced marks the start of the cardinals' isolation, and the start of the conclave

• Around 19:00 (18:00 BST), a set of smoke is released after the first ballot - and remember, you can watch the chimney by pressing watch live at the top of the page

On Thursday morning - if a new pope is not announced tonight - cardinals will have breakfast from 06:30 (05:30 BST) ahead of Mass at 08:15 (07:15 BST), before two more votes scheduled for later in the day.

Erwan Rivault
BBC News

One of the legacies of Pope Francis is that he has created a more global conclave to find his successor than the one that appointed him.

Of the 133 cardinals voting, 108 were appointed by him and more of them come from countries in Asia, South America and Africa than the conclave of 2013.

The number of voting cardinals from Europe and North America has decreased, while all other regions of the world have seen a rise.

Italy alone has 17 voting cardinals, the most out of any country, but this is down from 28 in the conclave that selected Pope Francis.

Asia has seen the biggest rise, more than doubling its number of voting cardinals, from 10 to 23.

Does the rise in cardinals from Asia and Africa mean we might see an Asian or an African pope?

We'll have to wait for the white smoke to find out.

Sarah Rainsford
Reporting from the Vatican

Image source, Getty Images

When the cardinals are shut into the Sistine Chapel later to choose a successor to Pope Francis, each one will have sworn an oath on the gospels to keep the details under wraps for life.

The same goes for every person inside the Vatican during the conclave: from the two doctors on hand for any emergency, to the dining-room staff who feed the cardinals.

All vow to observe "absolute and perpetual secrecy".

Just to be sure, the chapel and the two guesthouses will be swept for microphones and bugs.

"There are electronic jammers to make sure that phone and wi-fi signals are not getting in or out," said John Allen, the editor of Crux news site. "The Vatican takes the idea of isolation extremely seriously."

The famous lockdown is not only about keeping the voting process itself secret: stopping "nefarious forces" from attempting to hack it for information or to disrupt things.

The measures are also about ensuring the men in red total seclusion from the secular world and its influences as they prepare to vote.

Maryam Moshiri
Chief Presenter, BBC News

The sun has come out at the Vatican now and the crowds continue to build as everyone awaits the beginning of the conclave.

Pope Francis reached out to the youth and felt very strongly that young people need to be made to feel part of the Catholic Church.

I spoke to Michell, Marketa and Emily from the Czech Republic, who have come to see St Peter’s Square during a school trip.

I asked them how they felt about the prospect of a new pope.

"We are a little bit scared and excited and nervous a little bit .. because there will be a new Pope and he can bring some changes", said Marketa.

"I liked the old pope because he supported the LGBTQ community. We want a progressive pope," Marketa added.

Paul Burnell
Reporter, BBC News Online

Image source, Getty Images

The leader of the Roman Catholic church in England and Wales has said he and his fellow cardinals face a "big call" as the secret voting process to elect a new pope begins.

Cardinal Vincent Nichols is one of more than 130 electors who will be meet in the Vatican's Sistine Chapel during the conclave, with no contact with the outside world until they have chosen the next pontiff.

The Merseyside-born Archbishop of Westminster said he had been "getting to know" his fellow cardinals as many of them had never met before.

He said he felt "quite intimidated" knowing that the outcome of the election was "awaited by people all over the world and of many faiths".

Cardinal Nichols said the cardinals will have met "almost ten times" before the conclave in a series of meetings known as the Congregation of Cardinals.

The 79-year-old said there had been long meetings, "during which we have been very attentive to the contributions from cardinals across the world".

• Read more on why the Cardinals face a "big call" on next Pope

When asked about what they want in a new pope, American Catholics had mixed opinions.

"Conservative," one said.

"Progressive," the second said.

"Moderate," said a third.

Their responses sum up the tricky job facing the conclave as they choose the next head of the Catholic Church.

Sarah Rainsford
Reporting from Rome

In downtown Rome, in the churches and streets around the grave of Pope Francis, there is plenty of discussion about who might succeed him.

Santa Pudenziana, just one block back, is used by Catholics from the Philippines and some young churchgoers are hoping to see a Filipino pope.

Cardinal Luis Antonio Tagle - dubbed "the Asian Francis" for his focus on social issues - is considered one of the main contenders.

“I'm hoping for someone that will follow Pope Francis. Because he was so near to us youth, he really tried to understand us and gave us space in the Catholic Church,” Karine explains.

“We met Tagle a few times already, and he is really close to the youth. He’s very approachable. He seems someone you could call a friend,” Jessica says.

Although Italy is a Catholic country, she says young people are sometimes "judgy" here about those who are religious - unlike when she visits relatives in the Philippines.

“Having Tagle as the next Pope would be first of all an honour, but as well as an opportunity to us young people to feel heard,” she says.

Andrew Picken
BBC Scotland News

Image source, Reuters

This will be the second conclave in a row without a cardinal from Scotland.

Experts believe Scotland is still in the "sin bin" with the Vatican after the country's last cardinal, Keith O'Brien, was forced to resign because of sexual misconduct allegations.

In February 2013, Cardinal O'Brien was about to take part in the ancient tradition of electing a pope - and his enthusiasm was there for all to see.

During an interview with BBC Scotland News he showed off the neat brown rectangular voting paper to be used in the secret ballot.

But it would forever remain blank.

Cardinal O'Brien, who at the time was the Catholic Church's most senior cleric in Britain, had been due to meet his peers to decide who was to replace Pope Benedict XVI - but he never made it on the plane to Rome.

The 74-year-old Archbishop of St Andrews and Edinburgh resigned days before the conclave following The Observer newspaper's allegations of inappropriate behaviour towards priests dating back to the 1980s.

• Read more about the seismic blow to Scotland's standing in the Catholic Church

Sofia Ferreira Santos
Live reporter

As we've been reporting, the conclave to elect the new pope will begin today.

Inside the Sistine Chapel the cardinals will vote until a new pope is elected, with each round marked by a traditional smoke signal.

Black smoke signals the conclave has not yet come to a decision, and white smoke tells waiting crowds that a new pope has been chosen.

In 1958, the smoke led to widespread confusion when crowds saw white smoke - only for it to turn black moments later.

The BBC looks back at archive footage from 1958 to piece together what happened on that day.

Image source, AFP via Getty Images

The next pope will face a "slew of serious problems" when they step into their new role, former BBC Vatican correspondent and papal biographer David Willey told BBC Radio 5 Live Breakfast.

"Finance, paedophile priests, the future role of women in the Church, gender issues," Willey listed as some of the issues.

He said that although there had been a desire for someone "humble" like Pope Francis, the new leader would also have to be a good "administrator" if he wanted to succeed.

"The future power of the pope who is elected here in Rome, over the next few days, is enormous. It’s something of an anomaly in a world where you have very powerful politicians who pull the strings.

"You also have a humble, religious man who can show equal power in this strange world we’re living through today," Willey added.

Laura Gozzi
Reporting from Vatican City

Image source, AFP via Getty Images

A fresh breeze is blowing over Rome this morning.

The Mass ahead of the conclave is being celebrated within St Peter's Basilica and followed by people in the square, thanks to four giant screens set up near the colonnades.

An influx of faithful is expected later this evening, around the time of the first vote. For now, though, the atmosphere is quiet.

As hymns ring out from speakers, seagulls mill about the cobblestones.

Maryam Moshiri
Chief Presenter, BBC News

Here at the Vatican, people continue to gather ahead of the conclave - which is due to begin later today.

I spoke to Father Thomas Reese, a Jesuit priest and senior analyst for the Religion News Service.

He says he is looking forward to the conclave.

"I'm very excited about who is going to lead the church and be a spokesman for issues facing the world. We saw with Francis what an impact a pope can have, and we’re hoping that the one who’s elected will have that same kind of impact," he said.

I asked him for his thoughts on who might be elected.

"I think it’s all guessing at this point! If the conclave is over quickly it’s going to be one of the leading candidates like Cardinal Parolin, the current Secretary of State, but it’s everybody’s guess at this point."

Image source, Reuters

Following Pope’s Francis’s funeral last month, the Dean of the College of Cardinals, Giovanni Battista Re summoned cardinals to the Vatican to elect the new pope - the process known as the conclave.

Re presides over the Mass being celebrated this morning in St Peter’s Basilica ahead of the election of the new pope. He also led the Pope’s funeral.

Re was born on 30 January 1934 in the Italian commune of Borno, in Brescia. According to his Vatican biography, the 91-year-old holds a doctorate in canon law from the Pontifical Gregorian University in Rome and was ordained priest in 1957.

He then entered the Holy See's diplomatic service, during which he was posted to Panama and Iran. In 2001, Pope John Paul II proclaimed him a cardinal.

He was elected as dean of the College of Cardinals in 2020, and Pope Francis extended his term in February this year.

He participated in the conclave of April 2005, which elected Pope Benedict XVI and in the conclave of March 2013, which elected Pope Francis.

Image source, Reuters

The cardinal leading the Mass before the conclave, Giovanni Battista Re, has called on his peers to choose a leader who can guide the Catholic Church during what he calls a "difficult and complex" point in time.

"This is a strong call to maintain the unity of the Church... a unity that does not mean uniformity, but a firm and profound communion in diversity," he said during Mass.

Re, who is 91, is too old to vote in the conclave. Voters need to be under the age of 80.

He emphasised that the vote was of "exceptional importance" and that cardinals needed to set aside "every personal consideration".

Image source, Getty Images

The new pope has to be chosen by the Catholic Church's most senior officials, known as the College of Cardinals.

All men, they are appointed directly by the pope, and are usually ordained bishops.

There are currently 252 Catholic cardinals, just over 130 of whom are eligible to vote for the new pope.

The others are over the age of 80, which means they cannot take part in the election, although they can join in the debate over who should be selected.