In the early 1700s the Qing Dynasty began a long slow decline. As the population of China grew, it became more difficult to rule them. Leaders in the government raised taxes and kept the money for themselves. The peasants became poorer, while the wealthy became richer.
In 1850, a revolt known as the Taiping Rebellion greatly weakened the Qing Dynasty, and led to their being overthrown a few decades later.
The same fence that shuts others out shuts you in.
James Cook was the first person to cross the Antarctic Circle in 1773.