In Cíes found helpful attributable to Mesolithic (10,000 years ago) but have not yet found the remains of prehistoric stages following (Neolithic, Chalcolithic and Megalithic).
The first settlement of that we have clear evidence of Iron Age settlement is the Iron Age located on the western slope of Mount Faro. It is dated between 600 and 100 BC The inhabitants of this town were fed abundant fish and shellfish from the coast. Also included in your diet crops, hunting and eggs.
The Romans also came to the Cies islands which they called "insulae deorum" or Island of the Gods. Found ceramics and even a gold ring dating from the second century AD
In the eleventh century Benedictine monasteries first appear they were attacked by the Normans and reoccupied in the late thirteenth century. In the fourteenth century the monastery relocates with the order of the Franciscans.
In the XVI-XVIII centuries the island suffered continuous attacks from pirates like Sir Francis Drake and continuous warships berths English and French.
From the first half of the nineteenth century the situation was peaceful and installed fisheries and warehouses. You can see many dilapidated abandoned buildings from this time on the island. Its inhabitants lived by fishing, agriculture and livestock goats and sheep.
In 1840 ordering its annexation to the municipality of Vigo. Between 1851 and 1853 he built the first lighthouse, the Faro Monte dam and later joining the two islands.
Until the mid-twentieth century lived many families were leaving the islands because of the limited resources that were there. Today there are still a few houses built in the years 60-70.
In 1980 they were declared Natural Park and today belong to the National Maritime-Terrestrial Park of the Atlantic Islands of Galicia along with the islands of Ons, Sálvora and Cortegada..