Case of Duke Zhao of Song Attempting to Remove the Princelings and Yue Yu Resigning as Minister of Justice

Upon ascending the throne in 619 BC, Duke Zhao of Song resolved to eliminate the numerous princelings—junior members of the ruling house—to consolidate his power. Yue Yu, the Minister of Justice, remonstrated, famously arguing that the ducal clan was like the branches and leaves protecting the root; stripping them away would leave the trunk exposed. The duke ignored the counsel. Infuriated, the Mu and Xiang clans, leading the capital's populace, attacked the ducal palace and killed the officials Gongsun Gu and Gongsun Zheng. Facing a crisis, the six senior ministers mediated between the ruler and the clans. To pacify the conflict, Yue Yu voluntarily resigned his post as Minister of Justice and ceded it to Gongzi Ang, a princeling. The gesture restored a fragile peace, and Duke Zhao was able to proceed with his accession and the burial of his predecessor without further immediate bloodshed.

There was no formal trial. The violent confrontation was resolved through political compromise: the six ministers mediated a settlement, Yue Yu resigned his office of Minister of Justice in favor of a princeling, and Duke Zhao tacitly abandoned, at least temporarily, his plan to exterminate the princelings. The immediate crisis was defused, though the underlying tension remained.

The central dispute was whether a newly enthroned ruler held legitimate authority to purge potential rival claimants from his own clan. Yue Yu’s objection established the competing principle that the ducal clan served as an indispensable protective structure for the state, and destroying it would endanger the ruler himself. This pitted emerging monarchical absolutism against the entrenched kinship-based political order.

The case became a classical parable on the role of the ruling clan. Yue Yu’s arboreal metaphor—“the ducal house is the root, the princelings the branches and leaves”—entered the political lexicon, frequently invoked in later dynasties to debate the treatment of imperial kinsmen. The incident illustrated the volatility of clan-based politics in the Spring and Autumn period and foreshadowed the recurring internal strife that would plague the Song succession for generations.