Elizabeth was born in London to the Duke and Duchess of York, later King George VI and Queen Elizabeth, and was the elder of their two daughters. She was educated privately at home. Her father acceded to the throne on the abdication of his brother Edward VIII in 1936, from which time she was the heir presumptive. She began to undertake public duties during World War II, serving in the Auxiliary Territorial Service. In 1947, she married Philip, Duke of Edinburgh, with whom she has four children: Charles, Anne, Andrew, and Edward.
Who is Elizabeth's oldest child?