When Jorge Bergoglio finished studying chemistry at high school, his mother asked him what he would study next.
"Medicine," replied the skinny 19-year-old, according to his younger sister, Maria Elena.
Bergoglio's mother cleared a storage room in the family's working-class Buenos Aires home for him to use as a study. Every day, after his morning job in a lab, he would arrive home and disappear into the room.
One morning, though, his mother got a surprise. In the room, she found not anatomy or medicine texts but books on theology and Catholicism. Perturbed at his change of course, she confronted her eldest son.
"What is this?" she asked.
Bergoglio responded calmly: "It's medicine for the soul."
For the man who recently took over as the head of the Catholic Church, the shift from medicine to religion was the first of many in a career that has often defied expectations. It was also an early hint at what Argentines who know Bergoglio, now 76, describe as a steely determination—prepared even to mislead his mother—that lies beneath his charming and modest exterior.
"Jorge is a political man with a keen nose for politics," says Rafael Velasco, a Jesuit priest and former colleague who is now rector of the Catholic University of Cordoba, in central Argentina. "It's not an act, the humility. But it's part of his great capacity to intuitively know and read people."
The first pope from Latin America is also the first Jesuit pope. Like priests from other orders, Jesuits take vows of poverty, chastity and obedience, as well as a fourth special vow of obedience to the pope. They also make a promise to refrain from seeking high Church offices.
But Bergoglio rose steadily through the order's leadership posts and beyond, sometimes crossing swords with colleagues and once proving so meddlesome that a Jesuit boss dismissed him from the school where he was teaching. After being named a bishop he climbed through the Church hierarchy itself, rising to lead Argentina's largest archdiocese and eventually being named a cardinal.
Throughout his rise, Bergoglio eschewed the trappings of the positions he attained. As Archbishop of Buenos Aires, he famously took the subway from his one-room apartment in the Argentine capital instead of accepting the grand residence at his disposal. When his name emerged as a possible successor to John Paul in 2005, Bergoglio told family, friends and Argentine media that he didn't want to be pope. He loved Buenos Aires too much, he said. He had no desire to leave.
When the conclave named him successor to Pope Benedict earlier this month, he joked: "May God forgive you."
In Argentina, countrymen have expressed glee that one of their own has become the first non-European pope in 13 centuries. Francis has also charmed millions with his plainspoken banter, refusal to wear ornate vestments and his insistence that he pay his hotel bill in person the morning after the conclave. Some genuinely hope he can revive a Church roiled by scandal and undermined by rival religions and secularism, which many Catholics find to be out of touch with contemporary values.
At the same time, questions remain, not least about the exact nature of Bergoglio's role during the Argentine dictatorship's "Dirty War" against leftists and other political opponents in the 1970s and early 1980s. Some also point to his description of gay marriage as "the work of the devil" as proof of a hard-line conservatism.
The Vatican has moved quickly to defend Francis. The attacks, said Vatican spokesman Federico Lombardi, "reveal anti-clerical, left-wing elements that are used to attack the Church."
Interviews with nearly two dozen people, including his sister, colleagues from the Jesuit order in Argentina, his archdiocese and social circle, build a picture of a devout and dedicated priest whose scholarly grasp of Church doctrine rarely hindered his down-to-earth focus on charity, compassion and social work. They also reveal a calculating leader so used to getting his way that he once summoned a courtroom to him, rather than walk a few blocks to the courthouse.