The island is strategically located between the Greek mainland and Crete, and from ancient times was a crossroads of merchants, sailors, and conquerors. As such, it has had a long and varied history and has been influenced by many civilizations and cultures. 

There are archaeological remains from the Helladic period, contemporary with the Minoans and archaeological evidence of Kythiran trade as far as Egypt and Mesopotamia.

Kythira was independent, and issued her own coins in 195 after the Achaean defeat of Sparta. In Augustus’ time, it was again subject to Sparta.

Kythira continued to exist under the Roman Empire and its Byzantine successor state for centuries. 

Archaeological evidence suggests the island was abandoned about 700 AD.

When Saint Theodore of Cythera led a resettlement after the Byzantine reconquest of Crete in 962, he found the island occupied only by wandering bands of hunters. He established a great monastery at Paliochora; a town grew up around it, largely populated from Laconia.

Kythirans still talk about the destruction and looting of Paliochora by the pirate Barbarossa; it has become an intrinsic part of the Kytherian folklore. Kythira was at the mercy of Barbary pirates due to its strategic location in the Mediterranean. To intercept merchant vessels, islands along the trade routes were of course more interesting for pirates.

Kythira shared a common destiny with the other Ionian islands during the turbulent Napoleonic era, and is still regarded as one of them; it was counted as one of the Cyclades in antiquity.

The chief town of the island, Kythira has the Historical Archives of Kythira, the second largest in the Ionian islands, after Corfu.

Kythira is close to the Hellenic arc plate boundary zone, and thus highly prone to earthquakes. Many earthquakes in recorded history have had their epicentres near or on the island.