China is a geographical region in East Asia and Central Asia. With over one-fifth of the world's population, the majority of China exists today as a state known as the People's Republic of China, but it also refers to a long-standing civilization comprising successive states and cultures dating back more than 4,000 years.
With one of the world's longest periods of mostly uninterrupted civilization and the world's longest continuously used written language system, China's history has been largely characterized by repeated divisions and reunifications amid alternating periods of peace and war, and violent imperial dynastic change. The country's territorial extent expanded outwards from a core area in the North China Plain, and varied according to its changing fortunes to include multiple regions of East, Northeast, and Central Asia. (The term "China proper" is used by some observers and historians to describe the core territory historically home to the majority Han Chinese, as opposed to lands associated later with China such as what is now Xinjiang.) For centuries, Imperial China was also one of the world's most technologically advanced civilizations, and East Asia's dominant cultural influence, with an impact lasting to the present day.
By the nineteenth and early twentieth centuries, however, China's political, economic, and military influence declined relative to the growing regional power of Japan and the influence of Western powers. The imperial system in China ended with the establishment of the Republic of China (ROC) under Sun Yat-sen in 1912; however, the next four decades of ROC rule were marred by warlord control, the Second Sino-Japanese War during which the Empire of Japan occupied large parts of China, and the Chinese Civil War which pitted Chinese Nationalists against the Communist forces.
After its victory in the Chinese Civil War, the Communist Party of China under Mao Zedong established the People's Republic of China (PRC) in 1949, forcing the Nationalists to retreat and relocate the ROC government to the island of Taiwan, which it had governed since the end of World War II. Since then, the ROC has maintained administrative control over Taiwan, the Pescadores Islands, several islands off the coast of Fujian province including Kinmen and the Matsu Islands, and some islands in the South China Sea.