China knew the name of its idol in advance and worshipped it all the same. The "Mandate of Heaven" was no flattery of the throne but a stern covenant: authority is granted to a ruler only so long as he keeps virtue and care for the people; let him lose them, and Heaven withdraws the mandate, and rebellion becomes a lawful verdict. By the end of the second century, at the Han court, this moral covenant had withered into an empty rite. Real power was torn to shreds by eunuchs and the kinsmen of empresses; what governed was not duty but the squabbling of factions around a weakening throne. The form of the mandate remained while its content drained away — and form emptied of content is the very definition of an idol.
The collapse grew from below, out of hunger and despair. In 184 the Yellow Turban rebellion rose — a peasant tide under a Daoist teaching, whose leaders wore yellow turbans as the sign of "earth," destined to replace the spent "fire" of the Han. The rebellion was crushed, but at the cost of a fateful shift: it was put down not so much by the court as by the military governors of the provinces, and power flowed into their hands. Then came the wars of the warlords, and in 220 the last Han emperor abdicated, conceding that he had failed to hold the Mandate of Heaven. An empire that had stood four centuries ended not in a single blow but in a slow coming apart.
The captivity stretched across nearly four centuries of fragmentation. First the Three Kingdoms — three realms upon the bones of one — and then the long "period of division," when a unified China simply did not exist. This is the classic beat of bondage: not foreign chains but one's own disintegration, the impossibility of gathering up what has scattered, because the trust that bound it has departed. Whole generations were born and died without knowing a unified country — only borders, wars, and the succession of short-lived courts.
The return came as a gathering-up: reunification under the Sui dynasty in 589 and the flourishing under the Tang. But deeper than the events lies the doctrine itself, which this catastrophe tempered. The Mandate of Heaven made the cycle a law of history: the loss of virtue leads to revolt, revolt to fall, fall to a new dynasty, to which the mandate is handed anew and under the same condition. Here an ancient doctrine speaks the universal law almost word for word: a power that has forgotten what it was given for loses the right to be — and this is not the vengeance of enemies but a sentence that executes itself.