I know ancient China had been invaded and conquered multiple times by foreign nomadic groups coming from northeast Asia. Chinese civilization survived by eventually assimilating its conquerors over time. My question is about this process of assimilation and sinicization. When China was conquered, did the foreigners adopt Han customs/language because they really thought they were superior to their own or did they adopt them because they knew it was the only way they could control the vast empire with their smaller numbers compared to the total Han population. Were there other reasons they were sinicized?