<P> The title of "king" (wang, 王) was held by figurehead rulers of the Zhou dynasty, while the rulers of most states held the title of "duke" (gong, 公) or "marquess" (hou, 侯). A major exception was Chu, whose rulers were called kings since King Wu of Chu started using the title c. 703 BC . </P> <P> In 344 BC the rulers of Qi and Wei mutually recognized each other as "kings": King Wei of Qi and King Hui of Wei, in effect declaring their independence from the Zhou court . This marked a major turning point: unlike those in the Spring and Autumn period, the new generation of rulers ascending the thrones in the Warring States period would not entertain even the pretence of being vassals of the Zhou dynasty, instead proclaiming themselves fully independent kingdoms . </P> <P> During the early Warring States period Qin generally avoided conflicts with the other states . This changed during the reign of Duke Xiao, when prime minister Shang Yang made centralizing and authoritarian reforms in accordance with his Legalist philosophy between the years 356 and 338 BC . </P> <P> Shang introduced land reforms, privatized land, rewarded farmers who exceeded harvest quotas, enslaved farmers who failed to meet quotas, and used enslaved subjects as rewards for those who met government policies . As manpower was short in Qin relative to the other states at the time, Shang enacted policies to increase its manpower . As Qin peasants were recruited into the military, he encouraged active immigration of peasants from other states into Qin as a replacement workforce; this policy simultaneously increased the manpower of Qin and weakened the manpower of Qin's rivals . </P>

Who was involved in the warring states period