On September 9, 2015, Queen Elizabeth II thanked people from around the world for their messages of “great kindness” as she marked the day by becoming the longest-reigning monarch in British history.
The queen has worked with 13 different prime ministers in the course of her long reign and has met more people than any other monarch in history. Her rule, extending through decades of enormous change around the world, has also seen 13 U.S. presidents and seven popes in office.
