Joseon named an heir apparent for a childless king — the court purged itself twice over it

King Gyeongjong took the Joseon throne in 1720 at 31, already in poor health and, by the court's understanding, unable to father an heir. Two months into his reign the Noron faction pressed the obvious fix: name his half-brother Prince Yeoning heir apparent so the succession would not be left open. Gyeongjong agreed, and within weeks Noron went further, asking that the ailing king hand day-to-day state affairs to the new heir as regent.

The regency request is what broke the settlement. The Soron faction, which had backed Gyeongjong and distrusted Noron's ties to Yeoning, read the demand as a faction trying to install its own candidate in practice, not just in name. In December 1721 the Soron official Kim Il-gyeong accused the Noron leadership of attempting to usurp royal authority. The charge of treason was enough: four senior Noron ministers were executed and the faction's decade of dominance at court collapsed within weeks.

Naming the heir had settled nothing, because it never addressed who governed in the meantime. In 1722 fresh accusations — that Noron figures had plotted the king's assassination by blade, poison or deposition — produced a second, larger purge: close to twenty executions, roughly thirty deaths under torture, and over a hundred officials exiled. Prince Yeoning, the named heir, spent his brother's reign as a target rather than a groomed successor. Soron plotters once tried to have him killed under cover of a fox hunt; he survived only because the queen dowager intervened.

Gyeongjong died in 1724 after four years on the throne, and Yeoning succeeded him as King Yeongjo. One of Yeongjo's first acts was to reverse the purges: the two Soron officials who had driven the executions, Kim Il-gyeong and Mok Ho-ryong, were themselves put to death, and the treason charges against the dead Noron ministers were overturned. Yeongjo had watched the court destroy itself twice over a succession that was never actually in doubt, and it shaped the reconciliation policy — tangpyeong, balancing both factions in office — that defined the rest of his 52-year reign.