Head of state: Pope Francis
Cardinals elected the first Latin American pope in March 2013, choosing Cardinal Archbishop Jorge Mario Bergoglio of Buenos Aires to succeed Pope Benedict XVI, who had resigned over ill-health after a reign of eight years
At 76 he was only two years younger than Benedict at the time of his election, confounding expectations that the cardinals would opt for a younger candidate to lead the Catholic Church through the many challenges it faces.
Moreover, he has only one lung, which must raise doubts about his stamina in this demanding post.
He had broad appeal in the College of Cardinals, being conservative on homosexual rights but liberal on social issues especially alleviating poverty.
He is also the first pope from the Jesuit order of priests, who normally eschew promotion through the hierarchy to concentrate on scholarly and missionary work.
As head of the Jesuits in his native Argentina in the 1970s, he had to deal with the brutal right-wing military junta that ruled in 1976-1982, and was criticised by some for allegedly failing to do enough to help victims of repression - including two members of his own order.
His defenders insist that he did much to counter the generals behind the scenes.
As pope, he must deal with enduring scandals over clerical sex abuse and alleged corruption in the Vatican itself. He moved quickly to set up a group of top churchmen to advise him on how to reform the Vatican's bureaucracy in April.