The practice of becoming a duke was very common in Ancient China, marquis and marquesses too. The masses had always been divided into four classes: Scholars, Peasants, Artisans, and Merchants/traders - in that order.
Later, when graded into ten classes from most superior downwards, the practice of bowing before ones betters became the norm. Over the centuries, provinces gained in importance as centres of political and economic authority and increasingly became the focus of regional identification and loyalty.
The dukes took power from their luxury loving nobles on the basis that the country needed unifying. the Warring states period evidenced that. China’s first great era of disunity, known as the Warring States Period. Within the ideology of legalism, a monarch should seek to acquire as much political power as possible and apply strict laws to dominate all of society. Not surprisingly, this became unpleasant to live under and the dukes took action.
The regional Dukes gain de facto regional autonomy by taking power from his nobles and centralizing the state. Centralization became necessary as the states began to war among themselves and decentralization encourage more war.
When a dukedom was centralized, the shi would find employment as government officials, they could move from one state to another.When the Zhou dynasty was established, the conquered land was divided into hereditary fiefs that eventually became powerful on their own right. In matters of inheritance, the Zhou dynasty only recognized the patrilineal primogeniture as legal.