【正文】
g to the economic development of the area. During the Sui and Tang dynasties, the farming there had reached a level close to that of the central plains. Bai aristocrats backed by the Tang court unified the people of the Erhai area and established the Nanzhao regime of Yis and Bais. Its first chief, Piluoge, was granted the title of King of Yunnan by a Tang emperor. Slaves were used to do heavy labor。 whole “ free” peasants were subject to heavy taxation and forced to render various services including conscription into the army. Some of them, who lost their land, were made slaves. The Nanzhao regime lasted for 250 years. During that period of time, while maintaining a good relationship with the central government, the rulers cruelly oppressed the slaves and mercilessly plundered other ethnic nationalities through warfare. Productivity was thus seriously harmed. This caused slave rebellions and uprisings. Nanzhao’ s power came to an end in the year 902. Then a regime based on a feudal lord system, known as the Kingdom of Dali, was established. The kingdom adopted a series of measures such as abolishing exorbitant taxes and removing conservative ministers. As a result, social produ