At Rome’s Basilica of St. Paul Outside the Walls, the awaited arrival of Pope Leo XIV’s mosaic is sparking fresh fascination — and for some, old superstitions. As artisans prepare the golden medallion to join the long line of papal portraits above the nave, a familiar question reappears: What happens when there’s no more room?
The tradition of displaying portraits of every pope, beginning with St. Peter, stretches back to the 5th century under Pope Leo I.
These medallions — called tondi — encircle the church’s interior like a visual history of apostolic succession. But the sequence also fuels a curious legend: When all the empty spaces are filled, the world will end.
The legend isn’t official Church teaching — far from it. But it has circulated for decades, if not centuries, drawing attention each time a new pope is elected. It gained momentum after the 1823 fire that destroyed much of the basilica, and the images.
When Pope Leo XII began its reconstruction, the new series of mosaic portraits was limited in number. Since then, each new medallion has inched the church closer to the perceived “end.”
A limit?
With Leo XIV, the 267th pope, the basilica grows a bit closer to its architectural limit (though as tourists who have heard the legend might be surprised to find -- there are dozens of spaces still available).
Some visitors still quietly wonder: Will there eventually be no more room? And if there isn't?
The Church doesn’t endorse apocalyptic interpretations of the mosaics. In fact, the Catechism of the Catholic Church reminds the faithful that the end of time “remains hidden from all” (CCC 1040).
As early as the Gospels, Jesus warned against trying to calculate the day or the hour (Mark 13:32). Catholic teaching focuses instead on readiness, hope, and trust — not fear.
And yes, there is plenty of room for a lot more mosaics.
But there's something to be said for the legend
Still, the superstition has a poetic weight. It invites meditation on the mystery of time, mortality, and divine providence — concerns deeply human and universally shared.
The mosaics are not merely decorative; they’re a visual theology of sorts. Each portrait bears witness to a man chosen to carry the burden and blessing of Peter’s role, in a world constantly changing.
And the world has changed: from emperors to electric lights, from martyrs to modern media, the mosaic tradition has endured. Even after fires, wars, and reforms, the Church continues, mosaic by mosaic, pontificate by pontificate.
For now, the niche destined for Leo XIV’s image remains empty, though a gentle spotlight now shines where his face will soon appear. The delay is normal. Pope Francis’ own mosaic was installed nearly nine months after his election in 2013. The Vatican Mosaic Studio, a centuries-old institution behind many of Rome’s sacred artworks, is carefully preparing the piece.
When it’s unveiled, it won’t be a sign of the end, but of continuity. Faith doesn’t fear the future — it moves forward through it.
The real message at St. Paul Outside the Walls is not doom, but hope: the long line of successors, stretching through history, bears silent witness to a promise made on the shores of Galilee — that the gates of death will not prevail.
