When her father died in February 1952, Elizabeth—then 25 years old—became queen of seven independent Commonwealth countries: the United Kingdom, Canada, Australia, New Zealand, South Africa, Pakistan, and Ceylon (known today as Sri Lanka), as well as head of the Commonwealth. Elizabeth reigned as a constitutional monarch through major political changes such as the Troubles in Northern Ireland, devolution in the United Kingdom, the decolonisation of Africa, and the United Kingdom's accession to the European Communities and withdrawal from the European Union. The number of her realms varied over time as territories gained independence and some realms became republics. As queen, Elizabeth was served by more than 170 prime ministers across her realms. Her many historic visits and meetings included state visits to China in 1986, to Russia in 1994, and to the Republic of Ireland in 2011, and meetings with five popes and fourteen US presidents.
