Kasos, according to one version, got its name from the Phoenician word "ikas" which means foam. However, it is probably a pre-Greek word. Other ancient names of the island are Amphi, Astravi, Achni.
As can be seen from the archaeological finds in the natural port of Helartos which date back to the 16th - 15th centuries. BC, there was a permanent settlement in the area with close contacts with Crete.
So, Kasos has been inhabited since prehistoric times and the Phoenicians are mentioned as the first inhabitants of the island. Since ancient times, the island had developed maritime and commercial activity, since it held a strategic position, on the busy sea route from the north of Africa to the Black Sea, always being an important naval station for ships traveling to and from Egypt.
Cassos also took part in the Trojan War. It is mentioned by Homer in the list of ships that campaigned against Troy (Iliad B, v. 678-680).
Life during the Mycenaean years seems to have moved to the northern part of the island. Poli was a fortified Mycenaean acropolis and the only urban center of the island, in which continuous habitation was found throughout historical times up to the Early Christian period, confirming the written testimony of Strabo.
In the classical period, Kasos was inhabited by Dorians, conquered by the Persians and later was a member of the Athenian alliance and took part in the Peloponnesian War.
During the Roman period, it followed the fate of the rest of the Aegean islands and came under Roman rule, and then the island's population was transferred to Emporio.
During the Byzantine times it belonged to the Theme of Crete.
In 1207 it came under the possession of the Venetians and remained under their rule until 1287 when it was occupied by the Genoese Moresco brothers. Then, in 1306, the Venetians recaptured it.
During the Frankish period it will be ruled by the Kornaris family and then, in 1537, the Turkish admiral Hayreddin Barbarossa puts an end to the Venetian rule.
During the years of the Turkish rule, Kasos belonged to the privileged islands of the Aegean Archipelago and had its own system of self-government led by the body of the Demogerontia. Since the middle of the 18th century, the island's fleet has been developing and Kasos is a leading player in ocean-going shipping and trade. The Cassians exported plaster to Constantinople.
During the declaration of the revolution of '21 to include more than 80 ships. The contribution of the Cassian fleet to the struggle of the Greeks at sea was decisive, and especially the help it offered to revolted Crete, which is why the Turkish-Egyptian fleet, after suppressing the revolution in Crete, turned against Kasos.
The Greek fleet failed to help and after a heroic resistance Kasos was captured on June 7, 1824. Its naval power was destroyed and thousands of inhabitants were massacred or taken captive to Egypt. A few years later, however, the Kasiotes returned to the island.
With the finalization of the borders of the Greek state (London protocol of 1830), Kasos remained under the rule of the Ottomans, but they were never cut off from the trunk of the Greek state. On May 12, 1912, the long period of Italian rule began, but the Kassians did not remain apathetic and continuously, especially those of the diaspora who had immigrated to Egypt and America, organized with other twelve-nation organizations whose purpose was their union with Greece.
Italian rule was succeeded by German rule in 1943 and liberation and integration into the Greek state took place in 1948. It has
known many conquerors and disasters like most of the islands of the Dodecanese. Romans, Byzantines and Venetians ruled the island from time to time.

Editor: Fotini Anastasopoulou