She became Queen when her father, King George VI, died on 6 February 1952. Since 9 September 2015, Elizabeth II has ruled longer than any other king or queen in the history of the United Kingdom.[1] She has also ruled longer than any other living king or queen in the world as of the death of Thailand's Bhumibol Adulyadej on 13 October 2016.
The countries of which she is Queen are known as Commonwealth realms. Their total population is over 129 million. Although Elizabeth II is the queen of each country separately, and all sixteen are independent countries, Elizabeth II lives and spends most of her time in the United Kingdom. In all the other countries where she is queen, a person has been chosen to represent her. This person is known as the Governor General.
Elizabeth II is Queen and is interested in the running of her countries, but she does not tell the governments what to do. She has regular meetings with people from her governments, but it is they who run the countries. She performs ceremonies for the governments, gives out honours, and visits and supports many charities.
Since 1947, the Queen has been married to Prince Philip, Duke of Edinburgh. Prince Philip was born into the royal families of Greece and Denmark. Just before they were married, he became a citizen of the United Kingdom, and changed his name to Philip Mountbatten. He became the Duke of Edinburgh on the day he married, and became a Prince of the United Kingdom in 1957. The Queen and Prince Philip have four children, eight grandchildren and four great-grandchildren.