Piazza Navona was not born as a piazza. It was born as a stadium — the Stadium of Domitian, built in 86 AD for Greek-style athletic contests (not chariot races: those took place at the Circus Maximus). The stadium had an oval plan 265 meters long with a cavea seating 30,000 spectators. With the fall of the Roman Empire the structure was abandoned — but the perimeter walls remained, and medieval houses were built on top of them, forming the edge of the square. The name "Navona" probably derives from "in agone" — the games — corrupted over time. The narrow oval shape is that of the athletes' track.
In the Middle Ages and the Renaissance the square served as a weekly market. In the seventeenth century it became the representative center of the Pamphilj district — the family of Pope Innocent X (1644–1655). The family palace — Palazzo Pamphilj — stands on the western side. To give the square the character of a papal urban hall, Innocent commissioned Borromini to build the church of Sant'Agnese in Agone on the west side, and Bernini to build the fountain at the center. They were the two arch-rivals — in permanent competition — forced to collaborate on the same urban space.
The Fountain of the Four Rivers
Bernini's fountain (1651) has a precise narrative structure. At the center, the Egyptian obelisk — a symbol of universal power, imported to Rome by the Romans and now repurposed by the papacy as an emblem of its own universality. At the base, a perforated rock — the natural world — from which emerge four travertine and marble colossi personifying the four rivers symbolizing the four continents then known: the Nile (Africa, with its head covered — because its source was still unknown), the Río de la Plata (the Americas), the Danube (Europe), the Ganges (Asia).
Legend has it that the Río de la Plata colossus covers its eyes with its hand so as not to see Borromini's façade — and that the San Filippo Neri figure on Borromini's façade covers its eyes so as not to see Bernini's fountain. It is a delightful and completely false story: the fountain was completed in 1651, and Borromini's façade was begun in 1652. Bernini could not have responded to something that did not yet exist. But false traditions are sometimes more alive than truths.
The medieval and Renaissance life of the square
For almost a thousand years — from the 5th to the 17th century — Piazza Navona was a market. The market of Piazza Navona (active until 1869) was the main food and goods market of northern Rome. Stalls covered the entire length of the square; at the center, between one stall and the next, there were performances by jugglers, acrobats, medicine sellers, and itinerant preachers. The narrow oval shape — a legacy of the stadium — was perfect for a market: merchants lined up along the sides, the flow of buyers moving along the perimeter. What Domitian had designed as an athletic track functioned, centuries later, as a commercial street. Form survives use.
When the Pamphilj transformed the square into a representation of their papal power, the market did not disappear immediately — it coexisted with Bernini's fountain and Borromini's church for another century and a half. It was only with the new post-unification urban plan that the market was moved to Campo de' Fiori (1869). The square then became what it is today: a representative drawing room, with no commercial function, dominated by tourists and restaurants with outdoor tables. The loss of the market was the loss of the popular vitality the square had held for centuries.
The square as theater
In the 17th–18th century Piazza Navona was not just a space for circulation — it was an urban theater. Every Saturday in August the square was deliberately flooded: the fountain outlets were closed, and the floor of the square — slightly sloped and waterproofed by its paving — held the water up to ankle height. The carriages of the nobility splashed through the water, children played, and street vendors sold sorbets and ice cream. The "lake of Piazza Navona" was one of the main attractions of Baroque Rome, an eagerly awaited summer event codified as a ritual. The custom lasted until the early nineteenth century.
And here one must be precise: Baroque urban theater is not decoration — it is politics. The beautiful, animated square, with Bernini's fountain and Borromini's church, serves to demonstrate the power and magnificence of the papacy at a time when the Protestant Reformation had called Rome's authority into question. The beautiful city is a theological argument: if God upholds the Church, the Church produces beauty. The Fountain of the Four Rivers says: Rome governs the world — the four rivers of the four continents acknowledge the supremacy of the cross that crowns the obelisk. Baroque urban planning is propaganda in stone and water. Bernini knew it. And the pope knew it even better than he did.