At its end, Wei was swiftly overthrown by the Jin dynasty.
Many independent states eventually emerged from the weakened Zhou state and continually waged war with each other in the 300-year Spring and Autumn period, only occasionally deferring to the Zhou king.
By the time of the Warring States period of the 5th–3rd centuries after the state of Qin conquered the other six kingdoms and established the first unified Chinese state.
Since the introduction of economic reforms in 1978, China has become one of the world's fastest-growing major economies. China is also a member of numerous formal and informal multilateral organizations, including the WTO, APEC, BRICS, the Shanghai Cooperation Organization (SCO), the BCIM and the G-20.
As of 2016 The PRC is a member of the United Nations, as it replaced the ROC as a permanent member of the U. During the 1950s and 1960s, after the defeat of the Kuomingtang in the Chinese Civil War, it was also referred to as "Communist China" or "Red China", to be differentiated from "Nationalist China" or "Free China"., though centralized authority was slowly eroded by feudal warlords.
Between the 10th and 11th centuries, the population of China doubled in size to around 100 million people, mostly because of the expansion of rice cultivation in central and southern China, and the production of abundant food surpluses.
The Song dynasty also saw a revival of Confucianism, in response to the growth of Buddhism during the Tang, However, the military weakness of the Song army was observed by the Jurchen Jin dynasty.
Its King Zheng proclaimed himself the First Emperor of the Qin dynasty (Qín Shǐhuáng or Shǐ Huángdì).
He enacted Qin's legalist reforms throughout China, notably the forced standardization of Chinese characters, measurements, road widths (i.e., cart axles' length), and currency.
However, they fell quickly when their conscription for public works and a failed war with Korea provoked widespread unrest.