It started: White smoke is waiting, after which it will be said: Urbi et Orbi

Before the start of the conclave, a solemn Mass, "Pro Eligendo Romano Pontifice", will be held in St. Peter's Basilica in the Vatican, presided over by the Dean of the College of Cardinals, Cardinal Giovanni Battista Re, followed by lunch.

The participants of the conclave will then gather in the Apostolic Palace, from where, with the hymn "Veni Creator Spiritus", the solemn procession will move towards the Sistine Chapel, where the cardinals will take an oath "to observe the greatest secrecy regarding everything that in any way concerns the election of the Roman Pontiff".

The conclave will officially begin in the Sistine Chapel after the papal master of ceremonies pronounces the famous Latin formula "extra omnes" (everyone out), at around 4:30 p.m.

Conclave participants are expected to vote several times a day until one candidate receives two-thirds of the vote plus at least one more vote, and after every second unsuccessful vote, the ballots are burned in a furnace.

If no pope is selected, the slips are mixed with cartridges containing potassium perchlorate, anthracene - a component of coal tar, and sulfur to expel black smoke from the chimney.

If a winner is voted, the ballots are mixed with potassium chlorate, lactose and chloroform resin to produce white smoke and publicly announce that the pope has been voted.

Among the favorites for the new pope are Vatican Secretary of State Pietro Parolin, head of the Italian Bishops' Conference (CEI) Matteo Cuppi from Bologna, Peter Turkson from Ghana and Filipino Luis Antonio Tagle.

After white smoke appears from the chimney, inside the Sistine Chapel the dean of the college of cardinals will ask the elected cardinal if he accepts the papacy, and if he accepts, that cardinal automatically becomes the new Roman Catholic head.

He then chooses the name by which he will be known as pope, as, for example, Jose Maria Bergoglio chose the name Francis or Joseph Ratzinger - Benedict XVI, since the same name was chosen by 15 popes before him.

The cardinal protodeacon, that is, the oldest cardinal deacon, will then go out to the central balcony of St. Peter's Basilica, from where he will announce to the world "Annuntio vobis gaudium magnum: Habemus papam" (I announce to you great joy: We have a pope).

After the announcement, the new pope appears on the balcony to greet the crowd in St. Peter's Square, traditionally wearing a white papal cassock with red liturgical vestments, to give the first blessing to Rome and the world, known as "Urbi et Orbi."

This represents a significant moment for the beginning of the papacy, where the new head prays for peace, for the Church and for the world, together with a special apostolic blessing.

After that, the first mass of the new pope is held, with the presence of cardinals, bishops and other clergy, as well as many pilgrims and believers.

The previous two conclaves, in 2005 and 2013, lasted only two days each.

Rome's Committee for Public Order and Security announced today that more than 4,000 members of the police force will be deployed to ensure security during the inauguration ceremony of the new pope, and local authorities are expecting hundreds of thousands of tourists in the city.

Pope Francis was elected at the conclave in 2013 after two days of voting, and died on April 21 at the age of 89 and was buried in Rome's Basilica of Santa Maria Maggiore.