When white smoke drifts up from the chimney above the Sistine Chapel in the coming days, it will signal to the Vatican and the world that a new pope is about to begin his reign.

And when that pope chooses his new name, the decision will also send a powerful signal about the direction he intends to take the church -- and the type of pope he intends to be, says William Portier, chair of Catholic theology at the University of Dayton.

"In the Bible, when you get a new job from God, you pick a new name or you're given a new name, and that's the idea -- they feel they've been chosen to do this very weighty job and they need a name that will sort of help them and inspire them," Portier said. “It’s also a signal to the rest of the church and the world.”

By some accounts, the naming tradition began with Pope John II. Named Mercurius at birth, he changed his name after assuming the papacy in 533, believing it would be inappropriate for the head of the Christian church to share the name of a pagan god.

But the roots may date back even further to the apostle Simon, a fisherman whom Jesus renamed Peter, appointing him to build his church after he was crucified. Roman Catholics consider Peter to be the first pope.

Since John II, it’s believed that all popes have chosen a new name, often assuming the name of a previous pope whom they admired or whose work they hoped to continue or emulate.

"Once they get to be pope, they can choose whatever name they want," Portier said. “It is possible to read too much into it, but definitely it has a meaning so it’s not frivolous to try to figure out what it is.

"They’re thinking about something when they choose this name; it’s not just something that they think sounds good -- they consider it to be a weighty thing.”

Pope John Paul II -- Benedict XVI’s predecessor -- chose his name to honour his predecessor, Pope John Paul I, who died just one month into his reign. By assuming his name, John Paul II signalled his intention to continue the previous pope's work during his papacy.

Pope John Paul I had also paid tribute to previous popes. His moniker was a composite of the names of two previous popes, John and Paul, who had guided the church through the tumultuous Second Vatican Council (known as Vatican II) in the 1960s. Many consider it to be one of the most important -- and controversial -- periods in the church's history, as leaders attempted to modernize relations between the church and the secular world.

"(Pope John Paul I) wanted to show he was not going to deviate from their path and would be faithful to what they had done," Portier said.

Pope Benedict XVI, whose decision to step down from the papacy for health reasons spurred the latest conclave, also chose a name that reflected previous church leaders whom he hoped to emulate.

One was Pope Benedict XV, who reigned during the First World War and served as a voice for peace; the other was a 5th century monk who sought solitude in the country and worked to spread the Gospel around Europe. Though he wasn’t a pope, he set an example that Benedict XVI hoped to follow.

Other choices throughout history have been slightly more political -- and strategic -- in nature.

Pope John XXIII, for example, managed to erase a purported papal imposter from the history books with his name choice.

During the Great Western Schism of the 1400s, three men had claimed to be pope at the same time, including one who took the name John XXIII. He was later declared an imposter or “antipope” and deposed, but historians and scholars have often debated whether he actually had a legitimate claim.

By choosing the name John XXIII when he became pope in 1958 -- which he said was in honour of his father and other previous popes who started their reign later in life, like him -- the 77-year-old pope effectively relegated the deposed papal claimant to a footnote.

“By taking that name, he erased the other pope from history, and he was a historian so he knew that,” Portier said.

While it's too early to predict who the next pope will be or the name he will choose, the choice will certainly indicate the direction he plans to take during his reign.

If the new pope were to choose the name Pius, for example, it would indicate deference to Pope Pius XI, who refused to cede the Papal states to Napoleon and as a result was put in prison where he later died. He became known as a pope who fought for the papacy's independence from secular states, clinging to church tradition, Portier said.

While many expect the College of Cardinals to elect a pope who will bring the church into a more modern era -- perhaps the first Latino or North American pope -- the choice of the name Pius would signal the opposite, he said.

"If he chose that name, Pius, that would be a real surprise...to choose the name Pius would be to look back. It would be kind of scary to me and I think it would be scary to a lot of people."

Tradition dictates that other names are simply off limits. It would be considered bad form, for example, to choose the name Peter, since he is considered the first pope and is venerated as a saint.

If the Cardinals were to choose an African pope, he could choose to assume the name of one of several previous popes who had connections to North Africa. Pope Victor I, who reigned during the 14th century, hailed from North Africa, while Pope Miltiades and Pope Gelasius I were from Rome but are believed to be born to families of African origin.