Queen Elizabeth will become officially become the longest serving monarch in British history this week, beating out her great-great-grandmother Queen Victoria to take the title. During her almost 64-year-long reign, the queen has seen a remarkable amount of change in the world, but perhaps no change has greater affected her life than the remarkable decline of the British Empire.

When Elizabeth was crowned in 1952, the Britain still had a real empire, with more than 70 overseas territories. Even then, however, it was clear that the situation could not last. India, often declared "the jewel in the crown" for the Empire, had won its independence just five years before. In 1952, British troops were fighting independence movements in Egypt and Kenya. They would go on to lose both, and many others.

By 1979, the British empire was reduced to a few pockets around the world. The shrinking didn't stop, however. When Hong Kong was transferred to China in 1997, Queen Elizabeth's son Prince Charles himself dubbed it the "end of the Empire." In 2015, Britain has 14 overseas territories left. Outside of Britain's land in the Antarctic, which is vast but mostly unpopulated, the largest remaining British overseas territory is the Falkland Islands. At 4,700 square miles, the islands are a little smaller than Connecticut.

It's a far cry from the days when the sun never set on the Empire: In 1921, at the empire's peak, the British ruled around a quarter of the land on Earth. However, there is a small silver lining for Queen Elizabeth: She remains the monarch in 15 Commonwealth nations in addition to Britain.

More on WorldViews

Watch: How Britain built its empire on the seas