The United States of the Ionian Islands, a state and amicable protectorate of the United Kingdom, is created on November 5, 1815, as the successor state of the Septinsular Republic; it covers the territory of the Ionian Islands, in modern Greece.

The British depart the Ionian Islands on May 2, 1864, under terms of the Treaty of London, and the islands become three provinces of the Kingdom of Greece, though Britain retains the use of the port of Corfu.

The British had defeated the French fleet in Zakynthos on October 2, 1809, had captured Kefallonia, Kythera and Zakynthos, and had taken Lefkada in 1810.

The French had held out in Kerkyra until 1814.

The Treaty of Paris in 1815 had turned the islands into the "United States of the Ionian Islands" under British protection (November 5, 1815).

In January 1817, the British had ranted the islands a new constitution.

The islanders had elected an Assembly of 40 members, who advised the British High Commissioner.

The British had greatly improved the islands' communications, and introduced modern education and justice systems.

The islanders had welcomed most of these reforms, and had taken up afternoon tea, cricket and other English pastimes.

Once Greek independence was established after 1830, however, the islanders had begun to resent foreign rule and to press for enosis—union with Greece.

The British statesman William Ewart Gladstone had toured the islands and recommended that they be given to Greece.

The British government had resisted, since, like the Venetians, they had found the islands made useful naval bases.

They had also regarded the German-born king of Greece, King Otto, as unfriendly to Britain.

However, in 1862, Otto had been deposed and a pro-British king, George I, had been installed.

In 1862, Britain had decided to transfer the islands to Greece, as a gesture of support intended to bolster the popularity of the new king.