There were many native ethnic groups within Song China that did not belong to the Han Chinese majority. This included the Yao people, who staged tribal uprisings against the Song in Guangdong in 1035 and Hunan in 1043, during the reign of Emperor Renzong of Song (r. 1023–1064). Song authorities employed Zhuang people as local officials in what is now Guangxi and Guangdong, where the Song placed them in charge of distributing land to the Yao and other tribal groups. The Yao peoples and others on the empire's frontier were incorporated into a feudal system, or "fengjian shehui", which Ralph A. Litzinger says bypassed any possible native development of a primitive slave society, or "nuli shehui", since the Yao and others lacked a sedentary tradition. Although mainland Chinese states made efforts to settle parts of Hainan Island since the 3rd century BC, it was not until the Song that a concerted effort was made to assimilate the Li people of its highlands, who at times had fought against and repelled Han Chinese settlers. During the 11th century, the Man people of Hainan wreaked havoc by joining bandit gangs of ten to several hundred men. The statesman Ouyang Xiu estimated in 1043 that there were at least several thousand Man bandits residing in a dozen or so prefectures of mainland China.