Ios has been inhabited since the early Cycladic period, as proved by the archaeological excavations which brought to light various findings. These mark the existence of human life on the island during ancient years. The well-preserved remains of the walls of a castle and vessels, discovered at the west and north entrances of Chora, testify about the existence of a flourishing community. They also prove that the castle was inhabited since archaic period.
Various findings show that the history of Ios starts from the Prehistoric times. The island was originally inhabited by Careans, Pelageans, Achaeans and Phoenicians. In 1050 BC, the Ionians settled down in Ios. Various suppositions have been made about the origin of the name Ios. The most predominant and credible of all is that the island took its name from the Ionians. A second version supports that Ios owes its name to the many violets ("ion" in ancient Greek) that bloom on the island each spring.
Inscriptions, coins and some texts from ancient historians, among which Herodotus, testify that Ios is the birthplace of the mother (Klymeni) of the Greek epic poet Homer and in fact the great poet was buried there. This belief has become a great myth and an ancient site on the island side of the island is believed to be the tomb of Homer.
Excavations on the island, on the region of Psathi, have unearthed the remains of an ancient temple. A short distance away, there is a ruined aqueduct from the Hellenistic times. Ios established a democratic political system during the Classical period, when it became a member of the Athenian Delian League. In 338 BC, Ios came under Macedonian rule until 315 BC when it regained its independence. In the 2nd century BC, Ios came under Roman authority. The Romans were using the island as a place of exile, in the same way as the other Greek islands. Many churches were built during the Byzantine period in Ios history, using the columns and marbles of the ancient temples.
Byzantine and Recent history
During the years following the fall of the Byzantine Empire, Ios, like most of the Greek islands, suffered from many pirate raids and the inhabitants would hide in the fortified castle to escape from the savagery of the pirates. In 1204, the island was occupied by Crusaders and came under the authority of the Venetian family of Crispi in the 15th century. Ios became part of the Duchy of Naxos and the Crispi rebuilt a new castle on the ruins of the old one for a better protection against the fearsome pirates. That didn't stop the famous pirate Barbarossa from occupying Naxos in 1537 as well as almost all of the Greek islands.
The following years were very difficult for Ios, facing the constant attacks from the pirates and the Turkish fleet. During the Greek War of Independence against the Turkish domination, Ios took part in the Revolution, offering 24 well- equipped ships. The island finally gained its autonomy in 1829 and became a part of the Modern Greek State. Ios history very much resembles to the historical events of the rest of the Cycladic islands.