He is an austere Argentine prelate who, famously, lives in a modest apartment and prefers taking the bus rather than have a chauffeured car.
He has made headlines as much for his staunch defence of the poor during his country's economic crisis, as for his opposition to legalizing gay marriage.
The new pope is a man who blends a common touch with a faifthful adherence to church doctrine.
Observers noted right away that he chose to be called Francis, the first pontiff to adopt such a name, an obvious reference to Francis of Assisi, the 13th-century saint who embraced a life of poverty.
"I suspect what he says won't be that different from the previous popes but perhaps the way he says it, the tone, will show a greater pastoral sensitivity, a sense of the actual experience of people and the complexities of life," said Dan Donovan, professor emeritus of theology at St. Michael's College in the University of Toronto.
Francis had been a runner-up in the previous conclave in 2005. At the time, Sergio Rubin of the Argentine newspaper Clarin described the man then known as Cardinal Jorge Bergoglio as being cut from the same cloth as John Paul II – a man with conservative doctrinal views but progressive in social matters.
The last time there has been three consecutive non-Italian pontiffs was the Avignon papacy in the 14 th century. The Catholic church that Francis I inherits is just as troubled today.
The scandal-plagued Roman Curia is in need of good governance. The moral authority of the church has been undermined by sex scandals. Its doctrine is struggling to keep up with features of modern life people in developed countries take for granted, such as contraception, abortion or divorce without annulment.
He became archbishop of Buenos Aires in 1998 and Pope John Paul II proclaimed him cardinal in 2001. It was reported that he declined to live in the archbishop's palace, favouring a more frugal lifestyle.
As economic problems buffeted Argentina at the turn of the century, Cardinal Bergoglio spoke forcefully for the poor and against neo-Liberalism and the International Monetary Fund.
"We cannot permit ourselves to be overcome by inertia, to act as if we were impotent or to be frightened by threats," he said in a sermon.
He also clashed in 2010 with Argentine President Cristina Kirchner over her government's legalization of same-sex marriage and gay adoption. The law was a "destructive attack on God's plan," he said, calling homosexuality "a real and dire anthropological throwback."
Still, according to the National Catholic Reporter, in 2001, Cardinal Bergoglio visited a hospice for people with AIDS, washing and kissing the feet of a dozen patients.
The son of Italian immigrants, Francis was born Dec. 17, 1936, in Buenos Aires.
After studying chemistry, he turned to religion and was ordained in 1969. He is the first pope from the ranks of the Jesuits, an order known for its missionary work and intellectual rigour.
He rose through the ranks of the clergy as Argentina lived under military dictatorship and was said to have opposed the liberation theology movement.
In 2005, an Argentine human-rights lawyer filed a criminal complaint against the cardinal, alleging his involvement in the 1976 kidnappings of two priests, who were held by the navy for five months. At the time, a spokesman for Cardinal Bergoglio denied the allegations, which could be made under Argentine law with a low-threshold of evidence.
Later that year, he took part in the conclave that chose Benedict XVI. Italian media reports said he was the runner-up.
With files from Associated Press