Updated 0934 GMT (1734 HKT) April 21, 2020
Since 1952, there have been seven Popes, 13 US Presidents and 13 British Prime Ministers.
But there’s only been one British monarch.
Queen Elizabeth II has reigned for 67 years, which is longer than any British monarch in history and any current monarch in the world.
She was 25 years old when she ascended to the throne.
Look back at her life in the public spotlight: