Confucius held no significant office and his teaching had no state backing in his lifetime. That changed under the Han, when the classics were made the basis of official learning and scholars trained in them staffed the administration. From the Tang onward, recruitment by written examination in those texts became the route into government, and it remained so, with interruptions, until the examinations were abolished in 1905. For the better part of a thousand years, the texts a Chinese official had memorised were Confucian ones.
The Song brought a systematic revival, usually called Neo-Confucianism, which answered Buddhist metaphysics on its own ground. Zhu Xi organised the tradition around four texts (the Analects, the Mencius, the Great Learning and the Doctrine of the Mean), together with an account of principle and material force underlying all things; his commentaries became the examination standard. Wang Yangming later disputed his method, holding that moral knowledge is innate and inseparable from action rather than reached by the investigation of things.
The tradition shaped Korea, where it became the state orthodoxy of the Joseon dynasty, and had a substantial presence in Japan and in Vietnam.
The twentieth century was hostile. Reformers of the New Culture Movement identified Confucianism as the source of China's weakness and of the family and gender hierarchies they attacked; the Communist state was hostile in turn, and a campaign of the mid-1970s made Confucius an explicit target.
Since the 1980s the tradition has been rehabilitated in China, promoted as a source of social order and cultural continuity, and taken up by scholars arguing for its relevance to modern ethics and politics. Ancestral observance and the family obligations the tradition articulated remained widely practised across East Asia throughout, whether or not they were described as Confucian.