The Gran Paradiso National Park embraces a vast area of high mountains, ranging from valley bottoms at a height of 800 metres to the 4,061 metre-high peak of the Gran Paradiso itself. The first certain testimony of anthropisation of this area is a hill settlement of huts, dating back to the final phase of the Neolithic period, between the end of the 4th and the beginning of the 3rd millennium BC.
From this period onwards, probably during the transition from the Late Neolithic to the Early Chalcolithic period, new communities began to settle here, foreshadowing technological and metallurgical innovations, as confirmed by the discovery of an extensive necropolis and lithic industry in Villeneuve. Systematic occupation has been confirmed by the discovery of a vast area with megalithic monuments of worship and burial at the church of Saint-Martin-de-Corléans in the suburb to the west of the city of Aosta. This area had been actively used throughout the 3rd millennium BC. The Bronze and Iron Ages, on the other hand, left very few traces.
During the 2nd century BC, the Romans gradually colonised the Cisalpine region. The area was controlled by the Salassi and was later incorporated into the Augustan Transpadania Gaul. Rich in agricultural and mineral resources, it also controlled the Alpine belt and the regions to the north. The Salassi are mentioned by the ancient historians, Cato and Polybius from the beginning of the 2nd century BC, when they were forced to give their mines and valley bottom to the Romans following the victory in 140 BC of Appius Claudius Pulcher. Their final surrender to Aulus Terentius Varro Murena came in 25 BC, when they were sold as slaves. How the Romans organised the territory can be seen not only from the foundation of the Augustan colony of Augusta Praetoria Salassorum, but also from the layout of the numerous roads, such as the consular road to Gaul.
With the fall of the Roman Empire between the 4th and 5th centuries AD, the population decreased and the main settlements declined at the same time. Raids and unrest also marked the break-up of the urban fabric and the beginning of an initial process of ruralisation. The previous Roman road network became the corridor for a new ecclesiastical organisation.
The phenomenon of encastellation began in the 11th century. Defence structures to dominate the mountain tops, preside over the main communication roads in order to exact tolls and to control agricultural plots of land (the source of sustenance during invasions and civil wars) became widespread. From the mid 14th century, local wars ceased and there was a period of security, which saw the early strongholds abandoned and the construction of structures more similar to lordly homes in accessible areas. From 1559, following the Peace of Cateau-Cambrésis the Kingdom of Savoy was established and Emmanuel Philibert regained possession of these lands. He subjugated his vassals and prevented them from building or repairing any military structure.
In 1856, Victor Emmanuel II declared the Gran Paradiso Mountains a Royal Hunting Reserve to save the Alpine ibex from extinction after years of extermination first in Austria in the early 18th century, then in Switzerland at the beginning of the 19th century and again in France in the Dauphiné. The royal hunts continued into the early 20th century and enabled a close network of roads to be created through all the valleys in the Park and a corps of specialised guards to be set up. In 1920, Victor Emmanuel III donated the hunting reserve to the Italian State on condition it became a National Park to protect Alpine flora and fauna.