The first nobility to help the Zhou kings was the Duke Zhuang of Zheng (鄭莊公) (r. 743 BC-701 BC). He was the first to establish the hegemonical system (bà 霸), which was intended to retain the old proto-feudal system. Traditional historians justified the new system as a means of protecting weaker civilized states and the Zhou royalty from the intruding "barbarian" tribes. Located in the south, north, east and west, the barbarian tribes were, respectively, the Man, Yi, Rong and Di.



The newly powerful states were more eager to maintain aristocratic privileges over the traditional ideology of supporting the weak ruling entity during times of unrest (匡扶社稷 kuāng fú shè jì), which had been widely propagated during imperial China to consolidate power into the ruling family.

Dukes Huan of Qi (r. 685 BC-643 BC) and Wen of Jin (r. 636 BC-628 BC) made further steps in installing the overlordship system, which brought relative stability, but in shorter time periods than before. Annexations increased, favoring the several most powerful states, including Qin, Jin, Qi and Chu. The overlord role gradually drifted from its stated intention of protecting weaker states; the overlordship eventually became a system of hegemony of major states over weaker satellites of Chinese and "barbarian" origin.

The great states used the pretext of aid and protection to intervene and gain advantages over the smaller states during their internal quarrels. Later overlords were mostly derived from these great states. They proclaimed themselves master of their territories, without even recognizing the petty figurehead of Zhou. Establishment of the local administration system (Jun and Xian), with its officials appointed by the government, gave states better control over the dominion. Taxation facilitated commerce and agriculture more than proto-feudalism.

The three states of Qin, Jin and Qi not only optimized their own strength, but also repelled the southern state of Chu, whose rulers had proclaimed themselves kings. The Chu armies gradually intruded into the Yellow River Basin. Framing Chu as the "southern barbarian", Chu Man, was merely a pretext to warn Chu not to intervene into their respective spheres of influence. Chu intrusion was checked several times in three major battles with increasing violence - the Battle of Chengpu, the Battle of Bi and the Battle of Yanling; this resulted in the restorations of the states of Chen and Cai.