Queen Elizabeth II officially becomes Britain's longest-reigning monarch after passing the record set by her great-great-grandmother Queen Victoria. The Queen will have reigned for 63 years and seven months - calculated at 23,226 days, 16 hours and approximately 30 minutes at about 17:30 BST.

FACTS ABOUT QUEEN ELIZABETH AND VICTORIA:

Queen Victoria became queen at 18 while Queen Elizabeth ascended the throne at 25

Queen Elizabeth II rides in the same coach as Queen Victoria did for the annual State Opening of Parliament

Both queens were shot at by a lone gunman while out riding near Buckingham Palace

Elizabeth loves the private royal estate at Balmoral, which was bought by Victoria

Victoria ruled over an empire of 400 million people. Elizabeth is head of state for 138 million people

Queen Victoria became queen at the age of 18 and ruled for 63 years, seven months and two days.

Queen Elizabeth's reign has included 12 prime ministers, two more than served under Victoria.

Still ageing gracefully