Whereas, Caio Carlo Solino (Roman Historian of the 3rd century) claims in his Polyhistor that the foundation of the town is due to Archiloco Siculo. However, the origins of Ariccia remain uncertain. What we can be sure of is that it was founded before Rome. In fact, the existence of the town dates as far back as the 8th – 7th centuries BC as the defence wall built in peperino blocks and found in the high part of the town clearly suggests.

The ancient pre-roman town of Aricia was head of the Latin League. Its territory included Lake Nemi where the Sanctuary of Diana Nemorensis, the religious place of the Confederation of the Lazio populations, was located.

In the 4th century, under Roman rule, the Municipium of Aricia enjoyed a long period of splendour. Thanks to its fortunate position, just above the regina viarum (Appian Way) it was a crucial crossroad for trade and communications between Rome and the rest of the Empire. Evidence of this period is the ruin of Roman villas, such as the Emperor Vitellio’s villa (69 AD) of which the Nymphaeum and the cistern are still visible today.

When the works of the Appian Way were completed in 312 BC, the living area extended from the high acropolis towards the valley and tabernae (taverne), shops, warehouses, temples, public buildings and markets started to rise giving the appearance of a proper forum. Furthermore, the beautiful landscape and vicinity to the lakes made Ariccia a place of holiday spot for the most important people of that time.

In the year 827, in Medieval times, the town was invaded and destroyed by Goths, Vandals and Saracens, forcing the population to move to the acropolis (today town centre) hereby creating a new community.

At the end of the 10th century, Ariccia was ruled by Guido Conte of Tuscolo and in 1223, upon the orders of Pope Honorius III, member of the Savelli family, the castle became property of the Holy See until the end of the 15th century when it fell under the domain first of the Castello di Lariano and later of Genzano.

In 1473, Pope Sixtus IV handed the control of the town to the Savelli family who carried out many important works such as the Baronial Palace and the draining of the lake of Valericcia.

In 1661, the town was purchased by the Chigi family who enriched it with the magnificent and elegant masterpieces of Gian Lorenzo Bernini and other artists such as Carlo Fontana; the permanence of Pope Alexander VII was a particularly flourishing period during which the Chigi Palace, the adjoining Park, the Square and the Church of the Assumption are all superb examples.

Ariccia lived its most flourishing period from the end of the 18th century to half of the 19th century when it became an attraction for artists, intellectuals and decorators of the Gran Tour d’Italie. In the meantime, following the motu proprio announced by Pope Pius VII to discourage feudatories in Ariccia (owing to the high maintenance costs of the fiefs that the rich noble families would have to face), the Chigi family declined the control of Ariccia, but still maintained all their properties.

In 1854, the route of the Appian Way was rectified by the construction of a three-tiered bridge requested by Pope Pius IX, which passed through a dense wood (today Parco Chigi) linking Ariccia to Galloro Hill. During the Second World War, the bridge was destroyed by bombings and rebuilt in 1947.