Each of the 10 popes who preceded Francis had a claim on a unique spot in the 2,000-year history of the Roman Catholic Church. Here is a summary:
Benedict XVI (2005-13), born Joseph Ratzinger, will go down in history as the first pope in the modern era to resign voluntarily. The German theologian who enforced Church doctrine for a quarter-century before his election aged 78 picked up the baton of doctrinal purity wielded by his predecessor John Paul II. But his eight-year rule was marred by a raft of gaffes, scandals and insider intrigues.
John Paul II (1978-2005), born Karol Wojtyla, was the first Polish pope. Though a doctrinal conservative, the charismatic pontiff embraced modern ways of spreading the Gospel and achieved rock-star status among young people, travelling to more than 100 countries. He is credited with helping to bring down communism in eastern Europe. After being seriously wounded in an assassination attempt in 1981, he went on to suffer Parkinson's disease, the main cause of his very public decline.
John Paul I (1978), born Albino Luciani, reigned for only 33 days, scant time for the former patriarch of Venice to demonstrate his direct leadership style. But his disarming simplicity left him isolated within the Vatican. He was thought to have died of a heart attack amid suspicions that he was poisoned.
Paul VI (1963-78), born Giovanni Battista Montini, had a long career as a Vatican diplomat during which he was pope Pius XII's right-hand man. His election came at the height of the Second Vatican Council, which set him on a course of struggle over Church teachings in a modernising world. He was a flagbearer for peace and justice but drew fire for a 1968 encyclical that forbade contraception.
John XXIII (1958-63), born Angelo Roncalli, spearheaded the Church's opening to the world, launching Vatican II in 1962 to the dismay of an arch-conservative Curia. The chubby pontiff, nicknamed "Good Pope John", was popular for his bonhomie.
Pius XII (1939-58), born Eugenio Pacelli, was the wartime pope who had represented the Holy See in Munich and Berlin as Pius XI's top diplomat. The thin, aristocratic pope was accused of failing to do enough to prevent the Holocaust. His defenders say his efforts saved the lives of many Italian Jews who took shelter in convents.
Pius XI (1922-39), born Achille Ratti, settled the "Roman question", signing an accord with Mussolini in 1929 that created Vatican City as a sovereign state. He was staunchly anti-Nazi, the subject of a 1937 encyclical, and when Hitler came to Rome to visit Mussolini, Pius XI pointedly left town.
Benedict XV (1914-22), born Giacomo della Chiesa, sought to modernise the Church, encouraging popular piety, for example, by canonising Joan of Arc. But his efforts to stop the bloodbath of World War I through mediation and reparations fell on deaf ears. Ratzinger, in choosing to become the 16th pope Benedict, called him a "prophet of peace".
St Pius X (1903-14), born Giuseppe Melchiore Sarto, is the most recent pope to have been made a saint. The former parish priest was known for his piety, simple language and rapport with people. At the same time he was a conservative who opposed modernist tendencies within the Church, while launching reforms to canon law and taking a staunch position against slavery.
Leo XIII (1878-1903), born Gioacchino Pecci. He was the fourth longest reigning pope after Pius IX, St Peter and John Paul II. A humanist who composed poems in Latin, he is remembered for his social encyclical "Rerum Novarum" (On Capital and Labour) and supported Christian Democracy as against communism. He died at the age of 93.