Elizabeth II (Elizabeth Alexandra Mary Windsor, born 21 April 1926) is the Queen of the United Kingdom, as well as an additional fifteen independent states and their overseas territories and dependencies, since 6 February 1952. Though she holds each crown and title separately and equally, she is resident in and most directly involved with the United Kingdom. On 9 September 2015, her reign reached a milestone of 63 years, 7 months, and 4 days, the longest for any British Monarch in history.