The Merciless Parliament, a term coined by Augustinian chronicler Henry Knighton, refers to the English parliamentary session of February to June 1388, at which many members of Richard II's Court were convicted of treason. The session was preceded by a period in which Richard's power was revoked and the kingdom placed under the regency of the Lords Appellant. Richard had launched an abortive military attempt to overthrow the Lords Appellant and negotiate peace with the kingdom of France so he could focus all his resources against his domestic enemies. The Lords Appellant counteracted the attempt and called the Parliamentary session to expose his attempts to make peace. Parliament reacted with hostility and convicted almost all of Richard's advisers of treason. Most were executed and a few exiled. Parliament was dissolved after violence broke out in Kent and the Duke of York and his allies began objecting to some executions.
The kingdom of England was in the midst of the Hundred Years' War with kingdom of France, and the English had been consistently losing territory to the French since 1369. The losses were a politically sensitive topic and led to a shift in the English position after the death of Edward III, with his successor Richard II favoring peace while many of the landed nobility wanted to continue the war. The Wonderful Parliament in 1386 blamed the young King Richard's advisers for the military failures and accused them of misappropriating funds intended for the war. They authorized a commission of nobles known as the Lords Appellant to effectively take over management of the kingdom and act as Richard's regents. Richard refused to acknowledge the authority of the commission but lacked the power to challenge them. He began to devise a plan to secure his authority over the kingdom by raising an army among his allies and negotiating a secret peace with France so he could focus all his military forces against his domestic enemies.