Remnants found on the island, suggest that Ikaria had been inhabited 7.000 years ago by Pelasgians. According to ancient sources, major cities (Oenoe, Therme, Drakano) were built in 750 BC by Milesians. During the 6th century BC, the island was a part of the empire of the Samian tyrant Polycrates. At that time the ancient temple of goddess Artemis was built, at Nas region in the northwestern part of the island.
During the Persian Wars, Ikaria had been conquered by Persians and after its release in 479 (Battle of Mycale), became a member of the Delian League. Later on, the island had been successively dominated by Spartans, Macedonians and finally, in 133 BC, came under the influence of the Roman Empire.
In Byzantine times, the most significant town of the island , Oenoe, took the name of Doliche. Due to the strong earthquakes of the 4th and 8th century, as well as the many Arabic raids that followed, the population of Ikaria was dramatically reduced. The few remaining residents built towers and castle (Koskina, Kafalino, Miliopou), in order to protect themselves from the attacks of pirates .Moreover, at the same time, Ikaria started to get used as a place of exile for the members of the royal family.
Since 1911, the island passed successively into the hands of Venetians, Byzantines, Genoese, the Knights of Rhodes, and finally was conquered by the Ottomans in 1951. During the Ottoman Era, Ikaria had an autonomous administration system, providing a tribute to the Ottomans. Due to the piracy, the residents at that time, were forced to build their houses up on the mountains.
During the Greek Revolution of 1821, Ikarians fought against the Ottomans but without any significant victories. The island had been reunited with the rest of independent Greece for just two years (1828- 1830) before it passed once again to the Ottoman hands.
In 1912, he inhabitants of Ikaria revolted against the Ottomans, under the commands of Malachias and George Spanos, in whose memory statues and monuments have been founded and you can see them at the settlements of Evdilos and Chrysostomos. For five months Ikaria had remained independent and founded the “Free Ikarian State”. At last, in November 1912, the Greek fleet disembarked on the island and Ikaria was united once again with the Greek state.
During the years that the Second World War lasted, much of the population died from starvation and during the civil war years, the island became a place of exile for about 13.000 communists.