In 1809, the British Royal Navy defeated the French fleet in Zakynthos (October 2, 1809) captured Kefallonia, Kythera and Zakynthos, and took Lefkada in 1810. The French held out in Corfu until 1814. The Treaty of Paris in 1815 turned the islands into the "United States of the Ionian Islands" under British protection (November 5, 1815). In January 1817, the British granted the islands a new constitution. The islanders elected an Assembly of 40 members, who advised the British High Commissioner. The British greatly improved the islands' communications, and introduced modern education and justice systems. The islanders welcomed most of these reforms, and took up afternoon tea, cricket and other English pastimes.
Once Greek independence was established after 1830, however, the islanders began to press for Enosis – union with Greece. The British statesman William Ewart Gladstone toured the islands and recommended that having already Malta, giving the islands to Greece would not hurt the interest of the British Empire. The British government resisted, since like the Venetians they found the islands made useful naval bases. They also regarded the Bavarian-born king of Greece, King Otto, as unfriendly to Britain. However, in 1862, Otto was deposed in a coup by the Great National Assembly and a new king, George I from Denmark, was elected in his place.[citation needed]
In 1862, Britain decided to transfer the islands to Greece, as a gesture of support intended to bolster the new King's popularity (probably as a counterbalance to the newly established Italian state).
On May 2, 1864, the British departed and the islands became three provinces of the Kingdom of Greece, though Britain retained the use of the port of Corfu. On 21 May 1864 the Ionian Islands officially reunited with Greece. Prince Philippos of Greece and Denmark was born in Corfu in 1921 and grew up to become Britain's Prince Philip, Duke of Edinburgh. In 1923, following orders by Mussolini, the Italians temporarily occupied Corfu.