What name will he take? Because: Nomen est omen.
The choice of the Pope's name is programme. It gives an initial indication of the direction in which the new pope wants to steer the Church.
The next pope can choose from 83 names that his predecessors have borne - or, like Francis, adopt a name that has never been used before. The frontrunners among the papal names are "John" (23 times), "Gregory" (16), "Benedict" (16), "Clement" (14), "Innocent" (13), "Leo" (13) and "Pius" (12).
There is hardly any doubt: the new pope will also give himself a new name - a tradition that has been part of the papal election for around 1,000 years, like St Peter to St Paul.
To this day, it is an unwritten but always observed rule that certain names are considered taboo. These include the names of the twelve apostles, the four evangelists and St Joseph.
Of the great founders of religious orders such as Benedict, Dominic, Francis or Ignatius, only the name Benedict was able to secure a permanent place in the pool of papal names - until Francis was added in 2013.
No pagan names
In fact, it was this taboo that led to the first name changes. Out of respect and reverence for the first pope, the apostle Peter, two of his later successors dropped their baptismal names. Bishop Peter of Pavia therefore ascended the papal throne as John XIV (983-984), Bishop Peter of Albano as Sergius IV (1009-1012). It also seemed inappropriate to lead the Christian people with the name of a pagan god as pope. Thus the Roman Mercurio became Pope John II (533-535). He went down in history as the first pope to change his name.
In the following centuries, other popes continued this example. In 955, Ottaviano, whose first name was reminiscent of the first Roman emperor Octavian - Augustus, took over the papal office as John XII. Bruno of Carinthia, the first German to sit on the papal throne, found his baptismal name "too barbaric" and became Gregory V in 996.
With his papal name, Sergius IV (1009-1012) left behind the nickname "Pig's Mouth", which he bore among the people. From then on, it became the rule that every new pontiff took on a new name - with only three exceptions: Julius II (1503-1513), Hadrian VI (1522-1523) and Marcellus II (1555) kept their baptismal names.
The early name changes were based less on personal preference than on respect for Christian tradition and the desire to leave secular or pagan overtones behind. Later, the church leaders wanted to show that there was a difference between their previous person and the official person.
The Patriarch of Venice, Albino Luciani, made a special break when he chose a double name as John Paul I in 1978. He deliberately combined the legacy of his two predecessors, John XXIII and Paul VI, and thus created a novelty in the papal repertoire of names. His successor adopted the papal name and reigned as John Paul II for 26 years, 5 months and 17 days.
A big surprise
In 2013, the Argentinian Jorge Mario Bergoglio caused a surprise.
Not only was he the first pope from the Jesuit order and the first pope from Latin America, but he also took on a name that no one really expected: Francis.
A few days after his election, the Pope explained how this came about. The Brazilian Cardinal Claudio Hummes had told him: "Don't forget the poor!" This gave him the idea of naming himself after St Francis of Assisi (1181/82-1226). The saint and patron saint of Italy lived in radical poverty in order to serve God and mankind.
Will there soon be a Francis II or rather a Benedict XVII? When white smoke rises over St Peter's Square and shortly afterwards it says: "Habemus papam", it will become clear which choice the new pope has made.