The Natale di Roma, historically known as Dies Romana and also referred to as Romaia, is a festival linked to the foundation of the city of Rome, celebrated on April 21.

From this date, the Roman chronology derived its system, known by the Latin phrase Ab urbe condita, meaning 'from the founding of the City', which counted the years from this presumed foundation.

On a coin of the claimant to the throne Pacatianus, the number "1001" explicitly appears, indicating how the citizens of the Roman Empire understood they were at the beginning of a new era, Saeculum Novum.

The most revolutionary among the Mazzinians, Garibaldians, and some liberals celebrated the event, for instance, in the spring of 1849, when Rome, having recently become a free Republic that had overthrown the temporal power of the Pope, fought for survival.

[11] On April 3, 1921, during a speech in Bologna, the then leader of the Italian Fascist Movement Benito Mussolini proclaimed the anniversary of the founding of Rome as an official holiday of fascism.

[12] In the document that sanctioned the national-fascist fusion between the Italian Nationalist Association and the National Fascist Party, signed on March 16, 1923, representatives of the two political forces established to celebrate the unifying agreement with a manifesto containing an appeal for national unity, to be posted in all Italian cities on the evening of April 20, the eve of Natale di Roma, a day "signifying the occurred rebirth of Roman greatness".

During the event, a plan was announced to increase funding for historical reenactments and possible legislation aimed at regulating such celebrations to preserve and enhance cultural traditions.