Colonel Thomas Pride's soldiers excluded or arrested members of the House of Commons at Westminster on 6 December 1648. Those targeted were considered likely to continue negotiations with Charles I. The remaining Rump Parliament authorised the king's trial, making the purge a decisive military intervention in government.

Pride's Purge provoked lasting debate over whether revolutionary necessity could create legitimate authority. Satirists and Royalist poets depicted the reduced Parliament as an assembly ruled by soldiers rather than law.