The main and richest source of information about the civilization of prehistoric Thera is the settlement of Akrotiri which flourished during the first half of the 2nd millennium BC.
The site was first inhabited during the Late Neolithic (5th millennium BC) and during the Early Bronze Age (3rd millennium BC), as evidenced by meager finds. During the Middle Cycladic period, having developed close relations with Minoan Crete and mainland Greece, the settlement turns into a cultural, economic, commercial and artistic center of the Aegean that reaches its peak during the Late Cycladic I period. The terrifying eruption of the volcano (placed around 1650 BC) resulted in the total destruction of the settlement. However, the remains of this important cultural center were preserved under the thick layer of ash, giving important information about the era.
After being abandoned for 2-3 centuries, the island was inhabited again during the Mycenaean period (Monolithos hill). Palm trees settled on the island in the 13th century. BC and call it Kallisti, while from the end of the 12th c. BC it was colonized by the Lacedaemonians, led by Thera, from which its name derives.
The center of the island in historical years is located on the east coast, on the rock of Mesa Vounos, where the city of ancient Thera developed, which was continuously inhabited from the Geometric to the Late Roman times (9th - 3rd centuries BC). Thera in the 6th c. BC minted its own coin and tied its fortunes to the course of its metropolis, Sparta, during the Peloponnesian War. During the Hellenistic years the island developed and was used as a naval and military base of the Ptolemies, while during the Roman period it did not show much activity.
For the Early Byzantine period, the only important information we have is that from the 4th c. AD the island embraced Christianity and established the Diocese of Thira. After the 9th c. AD Thira joined the Aegean theme. Alexios I Komnenos (1081-1118) founded the church of Panagia Episkopi in Gonia, in the center of the island.
After the Conquest of Constantinople by the Franks (1204), Thira became the seat of one of the four Latin dioceses of the Aegean duchy and was granted together with Thirasia to Baron Iakovos Varotsis until 1335, when it was placed under the hegemony of Nikolaos Sanoudos , duke of Naxos, the capital of the Latin state. The Latins gave the island the name Santorini after the church of Agia Irene (Santa Irene), which they first encountered when approaching it. In the following years and until 1487, the island changed hands between the Frankish families of Sanoud, Crispi and Pisani. In 1487 it was annexed together with the Aegean duchy to Venice.
During the rule of the Franks, pirate raids decisively affected the economic, demographic and social life of the island. In addition, during this period, part of the inhabitants embraced the Catholic faith. In 1537, Santorini was plundered by Hairedin Barbarossa, and in 1566 it passed definitively into the hands of the Ottomans. But privileges were granted to its inhabitants, resulting in the rise of trade, shipping and the transformation of the island into a powerful center with a dynamic fleet and relations with the great ports of the time (Alexandria, Constantinople). Trade and shipping were the main sectors of development even after the establishment of the modern Greek state, which it joined in 1830, highlighting the economic independence of the island and its inhabitants. In 1941 Santorini initially joined the Italian administration, in the context of the occupation of the Greek territories by the Axis Powers. After the capitulation of Italy in 1943, the island experienced German occupation until its liberation.
An important event in recent history is the eruption of the volcano in 1956 and the devastating earthquakes, which resulted in the abandonment of the island by a large part of the population, underscoring the timeless role of natural forces in Santorini.