This chapter will consider the origins and use of impeachment in the fourteenth and fifteenth centuries. It will begin by exploring the period leading up to the Good Parliament of 1376, a time that was marked by national decline, a state of affairs which was exacerbated by Edward III's infirmity and Richard II's subsequent minority. This period of national decline resulted in the emergence of impeachment and parliamentary appeal as features of the parliamentary landscape, and also saw the threatened and eventual deposition of Richard II in 1399. Subsequently, impeachment fell into disuse, being used only once in Henry VI's reign, before its re-emergence in 1621. Against the backdrop of military and political turmoil, the role of the Commons and the Lords in the fourteenth and early fifteenth centuries are of significant constitutional importance. By the 1370s, the Commons had the right to be involved in lawmaking and could block grants of supply; thereby, it was sufficiently powerful as a body to force a financially poor and weak administration to permit the impeachment of leading royal officials. The subsequent use of impeachment against the king's officials would occur at times when the monarch was weak, as evidenced by the absence of impeachment during the Yorkist and Tudor periods. Between 1376 to 1450, impeachment was used to proceed against those accused of various offences, such as maladministration of justice and misconduct by judges.