King George VI died in February 1952; and as is the custom, his firstborn child succeeded to the throne. Princess Elizabeth was just 26 years old and married to Prince Philip. They had been blessed with two children by then, Prince Charles and Princess Anne. So her long reign began. The date of her coronation was June 2, 1953 (it took that long to prepare).
Update (June 11th 2016): Today marks Her Majesty the Queen’s official 90th birthday; for other (British) royalty related posts/poems, see:
Portrait of the Queen and Prince Philip taken by celebrity photographer Annie Leibovitz to mark the Queen’s 90th birthday. Copied from the Internet)
Diamond Jubilee, 2012 (original post):
Yesterday, Her Majesty Queen Elizabeth II addressed both Houses of Parliament here in London to mark her Diamond Jubilee just as she did during her Silver and Golden Jubilee years. She has already begun touring the UK; no mean feat at the age of 85 years nor for Prince Philip who is 90.