Today in History, February 6, 1952:

Treetops Hotel, Kenya.

While on a tour of colonial assets, Princess Elizabeth is notified that her father, King George VI, had passed, ascending her to the throne. She chose to keep her name, becoming Queen Elizabeth II of the United Kingdom, including England, Canada, Australia, New Zealand and the Commonwealth. At that time the Empire included many other nations that have since become independent.

Queen Elizabeth, who had been the heir apparent since 1936, still reigns after 68 years, making her the longest reigning sovereign of the British Empire.