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.