The island of Asinara preserves archaeological evidence dating back to the Neolithic period, visible at Piano Campo Perdu, Campo Faro and La Reale. More common are the signs of significant anthropic occupation in the Roman era. In his Naturalis Historia, Pliny the Elder mentions Asinara for the first time calling it “Herculis Insula”, a name which was then extended to the small island of Piana.
The largest concentration of traces dating back to this period can be found in the area of the Lazaret, a wide plain overlooking the best port of call on Asinara, that of Cala Reale. The chronology of this evidence – mid 1st century BC – and its position, lead us to think that the structure of the Roman settlement on the island can be linked to the foundation of Turris Libisonis (Porto Torres), interested in exploiting the rich reserves of grey granite in the areas of Cala S. Andrea and Cala Reale.
In the late Middle Ages, the island lost many of its inhabitants due to incursions by the Arabs. During the period of the first administrations when, around the middle of the year one thousand, Sardinia was divided into 4 kingdoms or giudicati, in turn divided into curatorie, it was part of the curatoria of Nurra, owned by the Doria and occupied by communities of fishermen.
In 1325, the Doria seized it and subsequently, in 1331, it was granted to Sassari as a grazing area. During the wars between Aragona and Arborea, the island was the scene of wars, and then remained deserted. The fishermen who came there were unable to avoid it becoming the base for pirate fleets who continued to disembark on Asinara for the whole of the following century.
When Sardinia passed under Savoy rule, the concession to Sassari was revoked and an attempt was made to colonise and populate the island by starting some agricultural activities. The experiment did not give good results and from the 19th century onwards, the island was used first as a Lazaret and then as a penal colony.