What were the major political developments in china during the early 20th century?

Before Europeans first arrived in Asia, China was one of the most advanced and powerful nations in the world. It was the most populous, was politically unified, and most importantly, it had mastered the art of agriculture. However, when Europeans first landed on Chinese shores, they found a nation that had revered to traditional culture and warfare. Industrialization was almost nonexistent.    

At the beginning of the 20th century, China was divided into sphere of influence with each powerful Western nation trying to exert as much control over it as possible. The Chinese resented foreigners control and expressed this at the beginning of the 20th century with the Boxer Rebellion.