Appalled Ukrainian officials pointed out that nostalgia for Russia’s imperial past was at the heart of the Kremlin’s invasion of their country. A Vatican spokesman was compelled to clarify that Francis, who has been emphatic in his opposition to the war, merely “intended to encourage young people to preserve and promote all that is positive in the great cultural and Russian spirituality, and certainly not to exalt imperialist logic and government personalities.”

The pontiff himself, though, was not all that chastened. A few days later, on a landmark trip to Mongolia, he summoned praise for the medieval empire forged by the great Mongol chieftain Genghis Khan, whose armies and those of his descendants rampaged their way from the Central Asian steppe to the river valleys of Central Europe. But rather than raising this blood-soaked history of conquest, Francis pointed to a unifying legacy of religious tolerance.

“The fact that the empire could embrace such distant and varied lands over the centuries bears witness to the remarkable ability of your ancestors to acknowledge the outstanding qualities of the peoples present in its immense territory and to put those qualities at the service of a common development,” Francis said at a meeting at the state palace in the Mongolian capital Ulaanbaatar.

In that history, the pope said, there’s a “model” that should be brought into our present: “May heaven grant that today, on this Earth devastated by countless conflicts, there be a renewal, respectful of international laws, of the condition of what was once the pax Mongolica, that is the absence of conflicts.”

The reaction to these remarks was more muted. Mongolia, an overwhelmingly Buddhist nation, was a curious choice for Francis’s 43rd Apostolic Journey. The pope has made a habit of venturing farther afield than his predecessors, but here was a country with fewer than 1,500 Roman Catholics and a deep Soviet-inspired tradition of atheism. Francis used his relative proximity to China to wish the “noble” Chinese people well, and urged Chinese Catholics to be “good citizens” — never mind the intensifying crackdown Beijing has carried out on the country’s religious communities, especially Muslims and Christians.

The Mongolian sojourn had an endearing strangeness: A delegation of Vatican cardinals and bishops found themselves in a lush valley for a local festival featuring wrestlers, feats of archery and throat singing. In the capital, the robed pontiff surveyed a troop of Mongolian cavalrymen clad in medieval armor.

But the pope’s invocation of Mongolia’s proud past — Genghis Khan remains a national icon in this country of 3.4 million people — was hardly a flight of his own fancy. As Vatican expert John L. Allen Jr. wrote, the pontiff’s trip was a voyage “almost 800 years in the making.”

In 1246, Vatican envoy Giovanni da Pian del Carpine made his way to the imperial camp of Guyuk Khan, a grandson of Genghis, with two letters from Pope Innocent IV urging the Mongols to cease their attacks on the lands of Christendom and beseeching Guyuk to convert to Christianity for his own salvation. Guyuk sent a bemused response written in Persian, calling on the pope to come instead to his court and pay homage to the ruler that clearly had God on his side.

“Through the power of God, all empires from the rising of the sun to its setting have been given to us and we own them,” the emperor wrote. On his visit this past week, Francis presented Mongolian officials with what was described as an “authenticated copy” of that 13th century letter.

For the Vatican and much of medieval Christendom, the realms of the Mongols were a source of fascination. Europeans latched onto rumors and whispers of the Mongols’ prowess, hoping for allies at a time when Crusader kingdoms in the Middle East were succumbing to the advances of various Turkish and Arab factions. In a dispatch to the papal court in 1145, a Syrian bishop wrote of the supposed Prester John, a powerful Christian priest and king in the East, descended from the line of the Magi, who had vanquished a great Muslim army in what is now modern Iran.

Historians have subsequently speculated this particular figure in question was actually Yelu Dashi, a Central Asian warlord whose domains would later be subsumed by Mongol invasions. Generations of medieval European travelers, including Carpine and the Venetian merchant Marco Polo, went in search of the myth of Prester John, a quest that was animated by the prevalence of Nestorian Christians — a community that existed for centuries outside the reach of the ecclesiastical hierarchies in Constantinople and Rome — in the courts of various prominent Asian potentates.

It’s the latent cosmopolitanism of that era that Francis sought to make as an example for our current moment. “In the 13th and 14th centuries, when the Mongolians controlled much of Eurasia, they fostered peaceful trading along the Silk Road,” wrote Jason Horowitz of the New York Times, who was among the Vatican press corps in Ulaanbaatar. “Mongolian nomads eager to do business would assess the religious affiliation of caravans crossing the Mongolian steppes and then extract from their coffers a Christian cross, a Quran or a Buddhist statue to facilitate trade.”