Ancient Times:
The first settlers of Santorini were Pre-Hellenes, who inhabited the island around 3.000 BC, during the Bronze Age. Later, Santorini was inhabited by the Phoenicians and the Dorians. It was an important center of the Minoan civilization during the 16th century, until its total destruction by a tremendous eruption of the volcano in 1550 – 15The island was first called “Strogili” (the round one), then “Kallisti” (the beautiful one) and “Thira” after Thiras, King of Sparta, who came to settle on the island.
During the period of the Persian War, the inhabitants of Thira initially refused to side with the Athenian Alliance, claiming that they were Dorians, although this did not last for long, as they finally sided with Athens. Later, they submitted under the rule of the Spartans.
Byzantine Era:
Little is known of Santorini’s fate during Roman domination, although when the Roman Empire was divided, it came under the rule of Constantinople. Like the rest of Greece, Christianity spread to Santorini during the 3rd century AD, and the island even had its own organized church and Bishop.
Venetian Rule: 
With the fall of Constantinople to the Fourth Crusade, Santorini came under the rule of the Venetians in 1204 AD. It is believed that Santorini became known by its present name during this period, when seamen from foreign lands had named the island after its church of Santa Irini, which gradually developed into Santorini. In 1207, Santorini was relinquished to the Duke of Naxos, while attempts were made to liberate the island. The island was taken by the Greeks for a short time, but it was recaptured by the Venetians in 1296 and stayed there until 1579, when Santorini came under Ottoman rule. In 1452, another violent volcanic eruption, which submerged half of the isle of Palea Kammeni, took place. This occurrence, along with the constant pirate attacks, caused much hardship for the island’s inhabitants.
Turkish Rule – Modern Times
During the Turkish Rule, Santorini kept most of its autonomy and even had an elected representative who represented the islanders before the Ottomans. The Catholic and Orthodox communities lived in relative peace, on different parts of the island. Santorini finally gained its independence in 1821, along with the rest of Greece. At that time, Santorini had one of the most powerful naval fleets in the country. During the period of WWII, Santorini was occupied by the Italians and the Germans until its liberation on October 18th, 1944.
In 1956, a great earthquake caused many deaths and the destruction of many buildings on the island. Several years passed before the Santorinians were able to live a normal life.
Today, Santorini, is one of the prime vacation destinations of the world with an extremely well-developed tourism infrastructure. Every year thousands of vacationers come to Santorini, to admire the island’s volcano, Caldera, sunset view and volcanic beaches.