The new pope, Jorge Mario Bergoglio(pronounced ber-GOAL-io), 76, will be called Francis. Chosen Wednesday by a gathering of Roman Catholic cardinals, he is in some ways a history-making pontiff, the first from the Jesuit order and the first pope from Latin America.

But Cardinal Bergoglio is also a conventional choice, a theological conservative of Italian ancestry who vigorously backs Vatican positions on abortion, gay marriage, the ordination of women and other major issues — leading to heated clashes with Argentina’s left-leaning president.

He was less energetic, however, when it came to standing up to Argentina’s military dictatorship during the 1970s as the country was consumed by a conflict between right and left that became known as the Dirty War. He has been accused of knowing about abuses and failing to do enough to stop them, during a period when as many as 30,000 people were abducted, tortured or killed by the dictatorship.

Despite the criticism, many here praise Cardinal Bergoglio — who likes the more humble title of Father Jorge — as a passionate defender of the poor and disenfranchised.

In 2001 he surprised the staff of Muñiz Hospital in Buenos Aires, asking for a jar of water, which he used to wash the feet of 12 patients hospitalized with complications from the virus that causes AIDS. He then kissed their feet, telling reporters that “society forgets the sick and the poor.” More recently, in September 2012, he scolded priests in Buenos Aires who refused to baptize the children of unwed mothers. “No to hypocrisy,” he said of the priests at the time. “They are the ones who separate the people of God from salvation.”

Though he is averse to liberation theology, which he views as hopelessly tainted with Marxist ideology, Cardinal Bergoglio has emphasized outreach to the impoverished, and as cardinal of Buenos Aires he has overseen increased social services and evangelization in the slums.

“I am encouraged by this choice, viewing it as a pledge for a church of simplicity and of ecological ideals,” said Leonardo Boff, a founder of liberation theology. What is more, Mr. Boff said, Cardinal Bergoglio comes from the developing world, “outside the walls of Rome.”

Jorge Mario Bergoglio was born in Buenos Aires on Dec. 17, 1936, to Mario Bergoglio, an immigrant from northern Italy, and Regina Bergoglio, a homemaker. He came relatively late to the priesthood, enrolling in a seminary only at the age of 21, after studying chemistry. He has had health concerns since his youth, having had a lung removed because of an infection.

By all accounts, he was a brilliant student who relished the study not just of theology but also of secular subjects like psychology and literature. He was ordained a priest a few days short of turning 33, and from that point on, his ascent within the church was rapid: by 1973, he had been named the Jesuit provincial for Argentina, the church official in charge of supervising the order’s activities in the country.

He remained in that post through 1979, and his performance during the Dirty War has been the subject of controversy. In 2005, shortly before the Vatican conclave that elevated Cardinal Joseph Ratzinger to the papacy, Cardinal Bergoglio was formally accused by an Argentine lawyer in a lawsuit of being complicit in the military’s kidnapping of two Jesuit priests whose antigovernment views he considered dangerously unorthodox.

The priests, whom he had dismissed from the order a week before they disappeared, were discovered months later on the outskirts of Buenos Aires, drugged and partially undressed. At the time the lawsuit was filed, the cardinal’s spokesman dismissed the accusations as “old slander.”

The lawsuit was eventually dismissed, but the debate has continued, with Argentine journalists publishing articles and books that appear to contradict Cardinal Bergoglio’s account of his actions. These accounts draw not only on documents from the period, but also on statements by priests and lay workers who clashed with Cardinal Bergoglio.

Emily Schmall reported from Buenos Aires, and Larry Rohter from Portland, Ore. Simon Romero contributed reporting from Rio de Janeiro, and  Mauricio Rabuffetti from Montevideo, Uruguay.