Although Pope Francis is a Jesuit, he chose his papal name not in honor of St. Francis Xavier, a co-founder of the Society of Jesus, but rather in honor of St. Francis of Assisi. It's a significant choice.

Cardinal Timothy Dolan of New York, a member of the 115-member conclave that elected Cardinal Jorge Mario Bergoglio as the 266th pope, told NBC News that the new pope explained his choice of name at the gathering Wednesday.

Vatican watchers said the election of Bergoglio was already a powerful signal of a renewed commitment by the Catholic Church to traditional Catholic theology. And in choosing to highlight Francis of Assisi, Bergoglio was explicitly honoring "a saint that transcends the Catholic Church and is loved by all people, a saint who reached out for simplicity, ... poverty and care for the poor," the Rev. Thomas Rosica, a spokesman for the Vatican, said in an interview with the Canadian Broadcasting Corp (CBC).

Francis (who was born in 1181 or 1182 and died in 1226) founded the Franciscan Order in his hometown, Assisi, in what is now the Italian region of Umbria.

Although he was never even ordained as a priest, Francis is considered one of the church's holiest figures and was canonized by Pope Gregory IX in 1228, only two years after his death, according to the Catholic Encyclopedia, which reflects the Vatican's official view of history. 

Slideshow: Pope Francis: His life before the papacy

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Cardinal Jorge Mario Bergoglio of Argentina was elected to lead the Roman Catholic Church following the resignation of Pope Benedict XVI. 

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Among other things, he's credited by the church with creating the first Nativity scene to celebrate Christmas in 1223.

Francis wasn't always so saintly. Born to wealth, he lived a playboy life that included blowing off his studies, according to a biography penned by Thomas of Celano, a friar who was a contemporary of Francis' and one of his first followers.

But in 1205 — as he was on his way to fight one of Assisi's many battles with its rival city of Perugia — Francis had what Thomas and other biographers describe as a vision in which he was told to return home. He did, taking up a life of prayer and solitude. On a subsequent pilgrimage to Rome, he reportedly gave all his money to the city's poor having exchanged his clothes with those of a beggar.

Shortly thereafter, Francis had another vision as he was praying in a rundown chapel in Assisi, in which Jesus commanded him, "Go, Francis, and repair my house, which as you see is falling into ruin."

Taking the command literally, according to Thomas' and other histories, Francis sold his home and his possessions to raise the money to rebuild the city's chapels. He became a street preacher, and by 1209, he and about 11 followers were making the rounds of Umbria's towns as itinerant preachers when Francis traveled to Rome to seek Pope Innocent III's blessing to establish a religious order. Final approval came the following year.

(The official history and admiring biographies of the time tell an entertaining tale of red tape and bureaucratic delays that kept Francis hanging around outside the Vatican for several days trying to get inside to see the pope.)

The order grew rapidly, and within a few years it had expanded into two others: one for women, today known as the Poor Clares, and another for pious laymen and women who choose to live a worldly life.

Followers were drawn by Francis' absolute devotion to living his life in close imitation of Jesus'. The burgeoning order celebrated poverty, so much so that in his "Testament," written shortly before he died, Francis said absolute poverty was his order's defining rule.

In a famous dictum history attributes to him, Francis argued: "You cannot starve a fasting man, you cannot steal from someone who has no money, you cannot ruin someone who hates prestige."

It is that philosophy that Pope Francis adheres to, even though he is not himself a member of the order, said Rosica, the Vatican spokesman.

"Cardinal Bergoglio has spent his life opening his arms to the poor, the destitute," he told the CBC. "Argentina is a beautiful country, but there are great pockets of poverty and injustice, and he was right there in the middle of all of this."

Church scholars predicted that the new pope would bring a sharp focus on ministering to the poor in the manner of St. Francis.

"He has a reputation for simplicity and for being utterly concerned about the poor," the Rev. John Padberg, director of the Institute of Jesuit Sources at Saint Louis University, told NBC station KSDK of St. Louis. "In all of the upheavals in Argentina in previous years, no matter what had happened, that was one of his main concerns."

Juan Martinez, an associate professor of Hispanic studies and pastoral leadership at Fuller Theological Seminary in Pasadena, Calif., said that while Pope Francis might be considered theologically conservative, he'll be "conservative with a human face."

"The reality of living amongst the poor and those who suffered in the majority world gives him a very different perspective from the previous pope," Martinez told NBC 4 of Los Angeles. "It is an experience that is more common among the majority of Catholics."

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Full coverage of Pope Francis from NBC News

Slideshow: Pope Francis: His life before the papacy

Marcos Brindicci / Reuters

Cardinal Jorge Mario Bergoglio of Argentina is both the first Latin American pope and the first Jesuit pope.

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Pope Francis is unique not just for being the first Latin American pope. He's also the first Jesuit pope, possibly signaling a renewed emphasis on traditional Catholic theology by the church.

The Society of Jesus, as the Jesuits are formally known, observes a vow of poverty, and as archbishop of Buenos Aires, the former Cardinal Jorge Mario Bergoglio was known for his accessibility and simplicity, said Michael Sheeran, president-elect of the American Association of Jesuit Colleges and Universities.

"Pope Francis took the bus to work every day," Sheeran said in a live online discussion of Bergoglio's election. "He sold the cardinal's residence and lived in a small apartment where he cooked for himself."

But that simplicity hides a steely determination to advance Jesuit principles, especially on the importance of traditional Catholic teachings and protection of the poor and the oppressed, Sheeran said. 

That determination emerged during Bergoglio's service as the top Jesuit leader of Argentina beginning in 1973, Sheeran said, noting, "He was a tough guy who made sure his men toed the mark."

"I think you'll find a man who is conservative theologically but very strong on matters of social justice," Sheeran said.

George Weigel, a senior fellow at the nonprofit Ethics and Public Policy Center who is a Vatican analyst for NBC News, agreed that the choice of Bergoglio "speaks to the church's commitment to the poor of the world and compassion in a world that often needs a lot of healing."

At the same time, "this is a John Paul II guy," Weigel said, referring to Pope John Paul II, who elevated Bergoglio to archbishop in 1998 and cardinal in 2001. As archbishop of Buenos Aires, "he tried to call that community back to orthodoxy," Weigel said.

The new pope has been a vocal opponent of abortion and especially of same-sex marriage, saying in 2010 that its role was to "seriously injure the family." He said the practice deprived children of "the human growth that God wanted them given by a father and a mother."

That position drew a rebuke from Argentine President Cristina Fernandez, who called Bergoglio a relic of "medieval times and the Inquisition."

Ultimate redemption for Jesuits
The Society of Jesus is the largest religious order of men in the Catholic Church, according to church statistics, and the largest single order of Catholic priests. But there has never before been a Jesuit pope, reflecting both the order's own reluctance to get deeply involved in church politics and its history as a polarizing force within Catholicism.

"I'm amazed (Francis) was selected," Sheeran said, because "the Jesuits steer clear of getting high-ranking jobs like this."

The society was founded in Rome in 1540 by St. Ignatius of Loyola and St. Francis Xavier as a movement devoted to living in the imitation of Jesus. 

From the beginning, the Jesuits have been aggressively evangelistic; they were the shock troops in the church's resistance to the Protestant Reformation of the 16th century and among the first missionaries to set up shop in such far-flung locales as India, Asia, and Central and South America, the Catholic Encyclopedia records.

That activism earned the society a reputation for political scheming by the 1760s, leading to its official suppression by Pope Clement XIV in 1773. Expulsion of the order quickly followed across much of the Catholic world, from France and Portugal to as far away as the Philippines.

"It thereby contributed to the polarization and politicization of the European public sphere in the age of enlightenment," Christine Vogel, a historian at the University of Rostock in Germany, wrote in a 2010 examination of the suppression.

The order remained in the wilderness for 41 years before Pope Pius VII restored its recognition after the Napoleonic Wars wound down in 1814.

In the modern era, the Jesuits have focused on social justice and education, having founded scores of prominent colleges  around the world, including 28 in the U.S., among them Georgetown in Washington, Boston College, Fordham in New York, Holy Cross in Massachusetts, Marquette in Milwaukee and Loyola in New Orleans. (An earlier version of this story inaccurately located Marquette University.)

That's in keeping with Pope Francis' own background — like his predecessor, Benedict XVI, Bergoglio is an academic as well as a priest.

Before he became a bishop in 1992, Bergoglio earned a doctorate in theology in Freiburg, Germany. He returned to Argentina and was a theology instructor at and later rector of the Philosophical and Theological Faculty of San Miguel in Buenos Aires.

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Pope Francis, the first man in the modern era from outside Europe to lead the Roman Catholic Church, prizes compassion, humility and simplicity — so much that he gave up his chauffeur in Argentina and took the bus to work.

He is the first pope to be a member of the Society of Jesus, a Catholic order founded in the 16th century by St. Ignatius Loyola. Its  members, known as Jesuits, take a vow of poverty and are known for their work among the poor and their scholarship.

“A man who calmly stands for what’s right and just,” Cardinal Edward Egan, the archibishop emeritus of New York, told NBC News. “A man of great compassion for the poor. That is what they point to first and foremost.”

During an economic crisis that gripped his home country over the last decade, Francis, then Cardinal Jorge Mario Bergoglio, asserted himself as a champion of the least fortunate and a defender of social justice.

“We live in the most unequal part of the world, which has grown the most yet reduced misery the least,” Bergoglio told Latin American bishops in 2007, according a recent profile in the National Catholic Reporter. “The unjust distribution of goods persists, creating a situation of social sin that cries out to Heaven and limits the possibilities of a fuller life for so many of our brothers.”

The new pope is known to be conservative on social issues. He has opposed abortion and gay marriage, and in 2010 he drew the ire of Argentina’s president when he said that gay adoption was a form of discrimination against children.

Vote: Was Pope Francis a good choice?

Argentina in 2010 became the first country in Latin America to legalize gay marriage. During the debate that preceded the change, Bergoglio called the bill “a plan to destroy God’s plan.”

“This is no mere legislative bill,” he said. “It is a move by the father of lies to confuse and deceive the children of God.”

Argentine President Cristina Fernandez de Kirchner shot back that the then-cardinal was speaking in terms “really reminiscent of the times of the Inquisition.”

As archbishop, Bergoglio had the option to live in a palace but chose a simple apartment, according to the National Catholic Reporter. He gave up a limousine for the bus, and cooks his own meals.

In the first act of his papacy, he chose the name Francis, becoming the namesake of St. Francis of Assisi, who gave up his riches and chose a life of poverty and prayer.

He was born in Buenos Aires on Dec. 17, 1936, his father an Italian railway worker. He was elevated to cardinal in 2001 by Pope John Paul II.

At 76, he had been considered by some observers too old for the job — particularly following Benedict, who said that at 85 he was no longer healthy enough to lead the church. Francis has only one lung, the other removed because of an infection when he was a teenager.

Still, Egan said: “I can assure you that he is not feeble in any way.”

Related: Single lung not likely to hinder new pope

His official biographer has said that Francis has both keen political instincts and self-effacing humility, and that he would encourage a kind of shoe-leather evangelism within the church. He is known to walk the streets of Buenos Aires to talk to the people.

He told priests in Argentina last year: “Jesus teaches us another way: Go out. Go out and share your testimony, go out and interact with your brothers, go out and share, go out and ask. Become the word in body as well as spirit.”

Perhaps helping him overcome the traditional reluctance to elect a Jesuit pope, he fell out of favor among some Jesuits in Argentina after he was elected to the title of Jesuit provincial in 1973.

Argentina was ruled in the late 1970s by a brutal military dictatorship, and many Jesuits were drawn to a progressive activist movement within the church known as liberation theology. Church leaders backed the dictatorship publicly, and Bergoglio discouraged priests from political activism.

Two of his Jesuit priests who followed the liberation theology movement were kidnapped from the slums by the military regime in 1976. Bergoglio personally appealed to the dictator, Jorge Videla, and had them freed. One of the priests later accused Bergoglio of effectively handing them over to the death squads in the first place.

Slideshow: Pope Francis: His life before the papacy

Marcos Brindicci / Reuters

Cardinal Jorge Bergoglio of Argentina was elected to lead the Catholic Church following the resignation of Pope Benedict XVI. 

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Bergoglio told his biographer, Sergio Rubin, that he often hid people on church property during the regime years and once gave his own identity papers to a man to help him get out of the country.

He later was sent to a school in northern Argentina to teach high school chemistry, an assignment seen as a type of exile, before the archbishop of Buenos Aires recalled him to be his auxiliary bishop.

“He’s a strong man, a man who can put up with criticism,” said George Weigel, NBC News’ Vatican analyst. “Cardinal Bergoglio put up with a lot of criticism from his brother Jesuits for many years.”

Francis earned a degree in chemistry and was ordained a priest in December 1969. He was named archbishop of Buenos Aires in 1998.

He was said to be the runner-up the last time cardinals met to choose a pope. An anonymous account of the 2005 conclave said that he had the support of some of the more liberal cardinals before giving up the fight and telling his backers to vote for Cardinal Joseph Ratzinger, who became Benedict XVI.

Related: New pope: 'Pray for me and I will see you soon' 

The account was attributed to a cardinal who leaked his diary to an Italian publication. It said that Francis, then Bergoglio, amassed 40 votes, more than half of what he would have needed for election, but still trailed Benedict after three ballots. His candidacy faltered on the fourth ballot, the diary said.

As Bergoglio cast his ballot beneath Michelangelo’s “Last Judgment,” the account said: “He had his face fixed on the image of Christ judging the souls at the end of time. A suffering face that implored: God, don’t to this to me.” The cardinal later declined to comment on the account.

By choosing a name no pope had chosen before, he may be signaling an era of rebirth for a church troubled by corruption and a sexual abuse crisis.

“We have to avoid the spiritual sickness of a self-referential church,” the new pope said before the conclave, according to the National Catholic Reporter. “It’s true that when you get out into the street, as happens to every man and woman, there can be accidents. However, if the church remains closed in on itself, self-referential, it gets old. Between a church that suffers accidents in the street, and a church that’s sick because it's self-referential, I have no doubts about preferring the former.”

The Associated Press contributed to this report.