The Roman emperor Vespasian had a tunnel built here to facilitate passage on the Via Flaminia at the narrowest point of the gorge (hence the name, from the Latina forulum, meaning "small hole").
During the Gothic Wars (6th century), the Ostrogoth King Totila had the pass fortified, but his troops were ousted by the Roman general Belisarius.
Between May 23 and June 12, 1849, soldiers of the Roman Republic, commanded by Colonel L. Pianciani, fought a skirmish in the pass with the Austrian army.
The seventies saw increasing destruction of the natural beauty of the surrounding landscape, as well as the deterioration of the road, due to the intense activity in quarries located within the Gorge.
In the 1930s, a profile of Benito Mussolini was sculpted on the slopes of Mount Pietralata by a local branch of the Guardia Forestale (State Forestry Corps), which was destroyed by partisans during World War II.