In the 3rd century BC, Hesychius mentions the name Orthonos . In the 6th century AD, Prokopios mentions the name Othoni and in the 10th century AD, Plinius mentions the name Thoronos .
It is said that Othoni was one of the points selected by the Romans to transmit urgent messages by lighting fires along a chain which started from Rome and went as far as the Eastern provinces of the Roman Empire.
In a document of 1383 , it is mentioned that Charles III of Durres gave the usufruct of the island to the Corfiot Th. Scalitis. This makes us speculate that the island must have been inhabited at the time, since they had an agricultural production amd they made profit.
However, the real settlement of Othoni started after the naval battle of Nafpaktos in 1571 , when the Turkish fleet was destroyed and the islanders started traveling more safely.
The first residents of Othoni were mainly families that arrived here from Paxos and Epirus . The people of Othoni had to fight several times against Berberian and Algerian pirates . In the center of the island, on the hillock ‘ Kalodiki’ at a height of 217 m., there is a monument of a , white stone Cross, in memory of the events that took place here in 1537 , when pirates under the notorious Khayr ad-Din Barbarossa , after a strong battle, slaughtered a large number of the island's population.