Liao, Western Xia and Jurchen Jin represented an important period in Chinese history for cultural exchange and integration between different ethnic groups. It was also a time of political contention between the south and the north. The three regimes were founded respectively by the Khitan, Tangut and Jurchen peoples. While preserving their own traditions and customs and creating their own writing systems, these peoples also absorbed cultural elements of other ethnic groups, particularly the Han political institutions and culture in establishing their central governments. Many emperors of these regimes had quite a profound understanding of Han culture. Government officials of the Southern and Northern Establishments of the Liao Empire respectively governed the Han people and people of Khitan and other ethnic groups based on their different traditions. Although Li Yuanhao of Western Xia was a strong advocate for his own ethnic culture and forced his people to wear a queue hairstyle, the political institution, administrative system and burial ceremonies of Western Xia were still heavily influenced by the institutional culture on the Central Plains. In reality, the Han scholar-officials from the Central Plains played a pivotal role in state governance. Among the three empires, Jurchen Jin was under the deepest influence of Confucianism. Their writing system incorporated parts of the Chinese script. All three regimes secured annual tributes from the Central Plains via wars, which constituted a major source of government revenues, and achieved political and social stability through internal management.