The bridge over the Natisone took years to build. According to local legend, the devil could have finished it in a single night.
The Ponte del Diavolo crosses the Natisone on two unequal stone arches, rising high above the river where it cuts through Cividale del Friuli. At the center, an enormous natural boulder supports the bridge's central pier.
According to local legend, the boulder was carried there in the apron of the devil's mother.
It is an unlikely explanation for an engineering achievement. But the history of the bridge reveals repeated efforts to establish a lasting stone crossing, well before the structure familiar today was completed.
A bargain across the river
The story begins with the people of Cividale unable to build a bridge strong enough to cross the river. Repeated efforts had failed, and the two sides of the town remained separated by a deep gorge.
Eventually, the devil appeared with an offer. He would build the bridge in a single night, provided he received the soul of the first living creature to cross it.
The townspeople accepted.
As the story goes, the devil worked through the darkness, gathering stone and raising the arches. His mother came to help, carrying the enormous boulder in her apron and depositing it in the river to support the central pier.
By morning, the bridge stood complete.
The devil waited to collect his payment. But the townspeople had found a way around their bargain. Instead of sending a person across, they sent an animal.
Some versions name a dog, others a cat or a pig. An older printed telling of the legend, preserved in the University of Trieste's digital collection, describes the townspeople rolling a round loaf of bread across the bridge to entice a dog to follow it.
Enraged at being cheated, the devil seized the animal and threw it against the rock below. According to that version, the dog's shape could still be seen in the stone, as though it had been turned to rock itself.
Other accounts end more simply, with the devil forced to accept the animal's soul and abandon his claim on the townspeople.
The variations are part of the tradition. They also reveal the story's central pleasure: the people of Cividale escape a dangerous bargain through their own ingenuity.
The bridge that took years
The documented history is less theatrical.
A wooden crossing had connected the two banks of the Natisone by the thirteenth century, but the river's floods made a more permanent structure necessary. Earlier efforts to establish a stone crossing had produced foundations and temporary arrangements rather than the finished bridge.
On December 11, 1441, Cividale's authorities contracted Iacopo Dugaro da Bissone to construct a stone bridge. Work began the following year, but progress was slow. The first arch was built before construction stalled in 1445, a year marked by an outbreak of plague.
The project subsequently passed to Erardo da Villaco, who undertook the second arch. By the time of his death in 1453, the bridge was largely standing, although finishing work remained. Bartolomeo delle Cisterne later took responsibility for the remaining work.
It is not difficult to see why such a structure might acquire a supernatural explanation. Where the records describe contracts, setbacks and years of work, the legend offers a bridge completed overnight.
The medieval structure did not survive entirely intact. On October 27, 1917, during the Italian retreat following the Battle of Caporetto, Italian forces destroyed the bridge in an attempt to slow the advancing troops. It was reconstructed under Austro-Hungarian supervision and reopened in May 1918, retaining the earlier bridge's two-arched form. The crossing seen today is therefore a reconstruction rather than an untouched medieval original.
The stone beneath the story
The boulder at the center of the Natisone is the detail that ties the accounts together.
It is not an invented feature added to make the legend convincing. The bridge genuinely rests on a massive natural rock in the riverbed, with its central pier supporting two unequal arches.
The structure rises roughly 22 meters above the river and extends about 48 meters across the gorge.
From the crossing above, the rock can appear to be little more than part of the masonry below. Seen from the riverbanks, its size and position become clearer.
The story of the devil's mother supplies an answer to a question the bridge itself seems to invite: how did such a large stone come to be exactly where the builders needed it?
The physical evidence explains the engineering. The legend explains the coincidence.
Neither requires the other to be true.
Standing above the Natisone, the two arches seem almost improbable against the steep limestone banks. The real builders needed years of work, successive craftsmen and an unusually placed boulder to connect the town.
In the legend, the devil needed only one night.