The seven islands are; from north to south:
Kerkyra usually known as Corfu in English and Corfù in Italian
Paxi also known as Paxos in English
Lefkada also known as Lefkas in English
Ithaki usually known as Ithaca in English
Kefalonia often known as Kefalonia, Cephalonia and Kefallinia in English
Zakynthos sometimes known as Zante in English and Italian
Kythira usually known as Cythera in English and sometimes known as Cerigo in English and Italian
The six northern islands are off the west coast of Greece, in the Ionian Sea.
The seventh island, Kythira, is off the southern tip of the Peloponnese, the southern part of the Greek mainland. Kythira is not part of the region of the Ionian Islands, as it is included in the region of Attica.
The islands were settled by Greeks at an early date, possibly as early as 1200 BC, and certainly by the 9th century BC. The early Eretrian settlement at Kerkyra was displaced by colonists from Corinth in 734 BC.
The islands were mostly a backwater during Ancient Greek times and played little part in Greek politics. The one exception was the conflict between Kerkyra and its mother-City Corinth in 434 BC, which brought intervention from Athens and triggered the Peloponnesian War.
Ithaca was the name of the island home of Odysseus in the epic Ancient Greek poem the Odyssey by Homer. Attempts have been made to identify Ithaki with ancient Ithaca, but the geography of the real island cannot be made to fit Homer's description. Archeological investigations have revealed interesting findings in both Kefalonia and Ithaca.
By the 4th century BC, most of the islands, were absorbed into the empire of Macedon. Some remained under the control of the Macedonian Kingdom and until 146 BC, when the Greek peninsula was gradually annexed by Rome.
After 400 years of peaceful Roman rule, the islands passed to the Eastern Roman or Byzantine Empire. Under Byzantine rule, from the mid-8th century, they formed the theme of Cephallenia. The islands were a frequent target of Saracen raids and from the late 11th century, saw a number of Norman and Italian attacks.
Most of the islands fell to William II of Sicily in 1185. Although Corfu and Lefkas remained under Byzantine control, Kefallonia and Zakynthos became the County palatine of Cephalonia and Zakynthos until 1357, when this entity was merged with Lefkada and Ithaki to become the Duchy of Leucadia under French and Italian dukes. Corfu, Paxi and Kythera were taken by the Venetians in 1204, after the dissolution of the Byzantine Empire by the Fourth Crusade. These became important overseas colonies of the Republic and were used as way-stations for their maritime trade with the Levant.