Racial segregation
In 836, when Lu Chun was appointed governor of Canton, he was disgusted to find Chinese living with foreigners and marrying them. Lu made segregation the law. He made it illegal for non-Chinese people to marry Chinese people or to own property. The law specifically banned Chinese from forming relationships with "Dark peoples" or "People of color." This meant foreigners like "Iranians, Sogdians, Arabs, Indians, Malays, Sumatrans", and others.