The 14 popes called Leo and the one new pontiff has chosen to emulate

This photo taken and handout on May 9, 2025 by The Vatican Media shows Pope Leo XIV during a mass with cardinals in the Sistine Chapel in The Vatican. (Photo by Handout / VATICAN MEDIA / AFP)

Of all the men who have become pope, those named Leo have occupied that office 14 times. Of those 14, four stand out either for good or for dubious reasons. The four are Leo I or the Great, Leo X, Leo XIII, and now Leo XIV. Except for Leo XIV who has yet to prove himself, each left a mark that reflected his time.

Probably the greatest of them all was Leo I or the Great (440 to 461), due to several achievements even as the Roman empire disintegrated. He established the Petrine Doctrine on the supremacy of Rome over such other big bishoprics as Constantinople and Alexandria. He was, Pope Benedict XVI, remarked in 2008, “truly one of the greatest pontiffs to have honoured the Roman See and made a very important contribution to strengthening its authority and prestige.” Besides taking the initiative to assert Rome’s predominance over European Christianity, Leo, in 452, successfully pleaded with Attila the Hun not to destroy what remained of the Roman Empire.

The Roman empire collapsed around 410 and with Christianity blamed for it, Aurelia Augustine had come to its defence with his City of God argument that previous world history had been preparation for Christianity. Leo’s pleadings helped to save his bishopric. In addition, he came to the defence of the Nicean Creed whose essence was threatened by those claiming Jesus the Man was different from Jesus the Divine or that the Man disappeared in the divine. His response, in his Leo’s Tome, was to assert the Man and the Divine were one and equal. By the time of his death in 461, he was recognised as a Doctor of Theology.

Roughly over a thousand years later, the very opposite of Leo I, became pope as Leo X in 1513 at age 37. His pontificate had little to do with piety; it was simply a matter of connections as a member of the House of Medici. He reportedly bragged: “Since God has given us the papacy, let us enjoy it” and he, a man of the Renaissance, enjoyed it promoting the arts so opulently that Rome became broke. Having authorised the sale of indulgences in 1517, he could not handle deep questions from an Augustinian monk, Martin Luther.

He failed to keep the Catholic Church intact. In the same year, the commoditisation of Africans through the Atlantic Slave Trade started supposedly to save ‘native Americans’ from the atrocities of enslavement. Africans were to supply the labour that was needed to create wealth for Europeans in Europe and the Americas.

While Leo X watched the breakup of Christendom in Europe and the start of turning Africans into commodities for trade, Leo XIII was different. He was an intellectual advocating the acceptance of modernity as he saw it. His encyclicals, the 1890 In Plurimis calling for abolition of slavery in Brazil, and the 1891 Rerum Novarum on the challenges of the Industrial Revolution his concern for social justice. He followed the scramble for Africa, particularly Italy’s desire to make Abyssinia part of its empire.

In the subsequent 1896 Battle of Adowa, Italians lost over 3,000 soldiers and the war which disturbed Pope Leo XIII who quickly turned diplomat and pleaded with Emperor Menelik II to release captured Italians. In accommodating Leo XIII, Menelik II released over 200 Italian prisoners of war, invoking Virgin Mary.

Leo XIII was the reason that Cardinal Robert Prevost chose the name Leo to continue with Leo XIII social justice work. Being Augustinian he would insist on reason as the guiding principle which tells him that artificial intelligence is one of the big challenges of the day. It can compound the miseries of the poor by making workers irrelevant. He is likely to be an activist Pope on the side of the weak, pushing social justice; just like Leo XIII.