Ithaca's main island has an area of 96 square kilometres (37 sq mi) and had a population in 2011 of 3,231. It is the second-smallest of seven main Ionian Islands, after Paxi. Ithaca is a separate regional unit of the Ionian Islands region, and the only municipality of the regional unit. The capital is Vathy (or Vathi).
Although the name Ithaca has remained unchanged since ancient times, written documents of different periods also refer to the island by other names, such as:
The island has been inhabited since the 2nd millennium BC. It may have been the capital of Cephalonia during the Mycenaean period and the capital-state of the small kingdom ruled by Odysseus. The Romans occupied the island in the 2nd century BC, and later it became part of the Byzantine Empire. The Normans ruled Ithaca in the 13th century, and after a short Turkish rule it fell into Venetian hands (Ionian Islands under Venetian rule).
Ithaca was subsequently occupied by France under the 1797 Treaty of Campo Formio. It was liberated by a joint Russo-Turkish force commanded by admirals Fyodor Ushakov and Kadir Bey in 1798 and subsequently became a part of the Septinsular Republic, which was originally established as a protectorate of the Russian Empire and Ottoman Empire. It became a French possession again in 1807, until it was taken over by the United Kingdom in 1809. Under the 1815 Treaty of Paris, Ithaca became a state of the United States of the Ionian Islands, a protectorate of the British Empire. In 1830 the local community requested to join with the rest of the newly restored nation-state of Greece. Under the 1864 Treaty of London, Ithaca, along with the remaining six Ionian islands, were ceded to Greece as a gesture of diplomatic friendship to Greece's new Anglophile king, George I. The United Kingdom kept its privileged use of the harbour at Corfu.
The origins of the first people to inhabit the island, which occurred during the last years of the Neolithic period (4000–3000 BC), are not clear. The traces of buildings, walls and a road from this time period prove that life existed and continued to do so during the Early Hellenic era (3000–2000 BC). In the years (2000–1500 BC) some of the population migrated to part of the island. The buildings and walls that were excavated showed the lifestyle of this period had remained primitive.
During the Mycenaean period (1600–1100 BC), Ithaca rose to the highest level of its ancient history. Mostly based on the Odyssey and oral traditions, it is believed that the island became the capital of the Ionian Kingdom-State, which included the surrounding lands, and was referred to as one of the most powerful states of that time. The Ithacans were characterized as great navigators and explorers with daring expeditions reaching further than the Mediterranean Sea.