Malta became a British colony in 1813, serving as a way station for ships and the headquarters for the British Mediterranean Fleet. It was besieged by the Axis powers during World War II and was an important Allied base for operations in North Africa and the Mediterranean. The British parliament passed the Malta Independence Act in 1964, giving Malta independence from the United Kingdom as the State of Malta, with Elizabeth II as its queen. The country became a republic in 1974. It has been a member state of the Commonwealth of Nations and the United Nations since independence, and joined the European Union in 2004; it became part of the eurozone monetary union in 2008.