1, socio-economic changes: the formation of some situations is related to socio-economic changes. For example, during the Southern and Northern Dynasties in China, the political and economic center of the Central Plains gradually moved southward due to the migration of northern nomads and climate change, which formed the situation of the Southern and Northern Dynasties.

2. Political struggle: Some situations are related to political struggle. For example, during the Spring and Autumn Period and the Warring States Period in China, the political and military struggles among the vassal states led to the division and diversification of China.