A Holy Mass is now being celebrated for the election of the new pope, in St Peter’s Basilica.

The service, which is televised, is presided over by Giovanni Battista Re, the 91-year-old Cardinal Dean who was also the celebrant of Pope Francis' funeral.

Image source, Reuters

Image source, Reuters

Image source, Reuters

Maryam Moshiri
Chief Presenter, BBC News

It's a rainy and drab morning here in the Vatican - but the weather has done little to dampen spirits as the excitement and anticipation builds ahead of the conclave later.

People are streaming into St Peter's Basilica to take part in a special mass this morning to mark the occasion and to pray for the 133 Cardinals who have to make the decision as to who is elected the 267th Pope.

This is arguably one of the most important conclaves in hundreds of years - as whoever becomes the new pontiff must decide whether to continue the legacy of Pope Francis, or take the Church and its 1.4 billion Catholics in a different direction.

Image source, Reuters

Cardinals play a central role in the papal election, known as a conclave. There are currently 252 Catholic cardinals, but only 133 will vote for a new pope as they must be under 80 years of age to take part.Here's a breakdown of the number of cardinals by continent:

1. Europe: 114
2. Asia: 37
3. South America: 32
4. Africa: 29
5. North America: 28
6. Central America: 8
7. Oceania: 4

The youngest member of the College of Cardinals is the Ukrainian-born Melbourne bishop Mykola Bychok, 45. The oldest is 99-year-old Angelo Acerbi, an veteran of the Vatican diplomatic service.

Image source, Reuters

During the voting period, the cardinals are cut off from the outside world – denied phones and access to the internet or newspapers.

They sleep and eat in Casa Santa Marta, a five-story guesthouse within the Vatican complex. The election is held in strict secrecy inside the Sistine Chapel, famously painted by Michelangelo.

Each cardinal votes for the candidate they wish to become Pope. They can vote for themselves if they wish. If any cardinals are too ill to be in the chapel, they can vote from their rooms.

A new pope is elected when a candidate has secured the support of 89 cardinals - which can take several rounds of voting.

In previous centuries, conclaves have gone on for weeks or months. Some cardinals have even died during the process.

The last two conclaves have concluded by the end of the second day.

Image source, Getty Images

Technically, yes. But it is highly unlikely.

The are no rules that forbid the Pope from being elected in the first vote, but it has not happened in centuries.

That first ballot is very important though, as the election is a numbers game: a two-thirds majority is needed to elect a new pope so cardinals will have to concentrate on candidates with a certain level of support.

The first - or first few - votes will indicate who could emerge as a potential candidate capable of creating enough consensus among the electing cardinals.

If today's vote doesn't yield a new pope, cardinals will go back to guesthouse Casa Santa Marta for dinner.

It is then, on the side-lines of the voting process, that conversations take place about whom to support.

Image source, Reuters

• From around 07:00 local time (06:00 BST), cardinals started to move into rooms in the Sanctae Marthae, a guesthouse in the Vatican (some will have moved on Tuesday)
• At 10:00 (09:00 BST), they will gather in St Peter's Basilica for a Mass

• At 16:30 (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 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.

From Thursday morning - if a new pope is not announced on Wednesday - cardinals will have breakfast from 06:30 (05:30 BST) ahead of Mass at 08:15 (07:15 BST), before two votes are scheduled.

We're just getting the first images from the Vatican this morning, where cardinals are gathering to start the process of electing a new pope.

The day is packed with rituals and ends with an evening prayer in the Sistine Chapel after a first, highly secretive, vote.

Image source, Reuters

Image source, Reuters

Image source, EPA-EFE/REX/Shutterstock

The cardinals have gathered in Vatican City to choose the 267th pope. In the morning, cardinals will take part in a Mass in St Peter’s Basilica.

Later, in the afternoon, the cardinals will walk in a procession along the Via delle Fondamenta to the Sistine Chapel.

This is where the highly secretive voting process takes place, beneath the famous Renaissance frescoes.

Later the world will witness the first smoke emerge from the Sistine Chapel chimney. If it is black then there will be more voting in the following days.

White smoke, of course, means a new pope has been chosen.

Image source, Getty Images

Cardinals from across the world are gathering in Rome to elect the next pontiff following the death of Pope Francis on Easter Monday.

We don’t know how long this process will take — previous conclaves have lasted only a few days, though in earlier centuries disagreements sometimes caused the meetings to stretch on for months.

Cardinals will take part in a Mass at St Peter's Basilica this morning and will later walk to the Sistine Chapel to cast their votes under Michelangelo's frescoes.

Once they enter the chapel, they will have no communication with the outside world until a new pope is elected.

Then we wait for smoke to emerge from the chapel’s chimney. If it's black, there will be more rounds of voting tomorrow. White smoke signals that a new pope has been chosen.

We'll take you through the day and will later, of course, be on the look out for the first signs of smoke. So stick with us.