Multidisciplinary analysis reveals the social inequality patterns in the Central Plains of the Eastern Zhou Dynasty in China

The Eastern Zhou Dynasty (771 - 221 BC), characterized by political instability, unbalanced economic development and frequent vassal - state hegemony wars, played a crucial role in promoting the development and evolution of social inequality in ancient China by intensifying class differentiation and wealth disparity. Previous studies have emphasized the dietary inequality among different social classes several years prior to death. Given that social inequality is a comprehensive concept, a more multi - dimensional investigation of the Eastern Zhou period is urgently required. Here, we present ancient DNA analysis, palaeoproteomics analysis, stable isotope data of oxygen, carbon and nitrogen isotopes, and radiogenic isotope ratios of strontium for 32 skeletons (6 nobles and 26 sacrificial victims) from Songzhuang Cemetery of the Eastern Zhou peried from Qi County, Henan Province, China. Our results show that the social inequality patterns in Songzhuang society are manifested in aspects such as sex, diet, and mobility. The dominant proportion of young women in sacrificial companions implies their marginalization at that time. The dietary differences based on class are significant, with nobles consuming more socially valuable foods (high protein and millet) than the sacrificial companions, who are further divided into two groups with different status based on diet, indicating internal differences. Class - based dietary differences have been formed since childhood, reflecting the solidification of social inequality patterns. The nobility showed a higher proportion of non-local phenomena, indicating their stronger mobility. At the same time, considering the long-distance migration of noblewoman and the kinship that only exists among the nobles, blood and marriage ties may be important means for the aristocratic class to construct and maintain their social status. Although class solidification is serious, this study still found the example of class crossing between two individuals in the M18 tomb.