The Meeting of Leo I and Attila

Deep in the left aisle of St. Peter’s Basilica, a work will stop you in your tracks—you’ll think you’re looking at a painting in the process of exploding. Except it’s not a painting; it’s a marble high-relief seven meters tall and nearly five meters wide, rising from near-flat at the wall to nearly full-body three-dimensional sculpture at the front. This is the greatest gamble in the career of Alessandro Algardi—the only sculptor of the 17th century who could stand his ground against Bernini.

The scene depicts a real historical event in 452 CE—the era’s most jaw-dropping diplomatic miracle: Attila the Hun, history’s most terrifying medieval invader, the “Scourge of God,” crossed the Alps with his army like a flood breaching a dam, prepared to swallow Italy. Everyone assumed Rome was finished. Yet Pope Leo I—unarmed, without any military force—decided to ride out alone and negotiate with Attila. Nobody knows what passed between them, but the result was: Attila withdrew.

Algardi transformed this historical mystery of “I don’t know what was said but the army left anyway” into a theological answer: divine miracle. In the upper half of the relief, Saints Peter and Paul appear in mid-air, swords drawn, diving from the clouds with the unmistakable expression of people about to do something decisive. Below them, Attila—the man who had the whole of Europe trembling—shields his face; his warhorse is backing away. Notably, Algardi didn’t depict Attila as a complete monster; his facial expression shows fear, shows revelation, shows some flash of humanity.

The difference in depth between the foreground and background creates a magic trick of forcing perspective into flat space: standing directly in front, you feel the foreground figures are about to step out and knock into you, while the distant figures in the background press toward you like an advancing army. This technique, which art historians call “multi-layer relief perspectivism,” was pushed by Algardi to its most extreme in history in this work. He wasn’t decorating the Vatican; he was writing a three-dimensional film in stone.

Algardi completed this work in 1654, but died in June of that same year before seeing it installed. This is his final work—and the most powerful summary of his entire career. In a career overshadowed by Bernini, who had the favor of popes, Algardi demonstrated with this relief: sometimes, all a person has is stone and decades of skill—and that can still render the viewer speechless.

ArtBuddy Interactive Challenge: At the very top of this “stone movie,” can you spot the two saints (Peter and Paul) diving down with drawn swords to “mediate” the dispute?