During the medieval and Tudor periods, the English Parliament had developed in close conjunction with the legal and judicial systems. Parliament was the monarch's ‘high court’ and exercised justice in the monarch's name. In addition to joint proceedings of the two Houses, for example, in cases of impeachment, the House of Lords possessed an appellate judicature and from 1621 re-established itself as a formidably effective and popular court of appeal. The abolition of the monarchy and the House of Lords in 1649 therefore raised major questions about Parliament's judicial and legal role. How far had the Lords' judicial powers been transferred to the unicameral Parliaments of the Interregnum? This issue emerged most starkly during the trial of James Nayler in 1656, and prompted calls for another House that would fulfil some of the functions of the old House of Lords and constrain the Commons' actions. Yet the creation of the Other House by the Humble Petition and Advice proved highly controversial, and sparked major debates over its status and powers during 1658–9. Furthermore, the Protectorate Parliaments regularly addressed issues relating to law reform, although the reality of what was achieved in this area fell far short of what Cromwell desired. Parliament's relationship with the law and the legal system remained highly contested throughout the Protectorate and was a further source of division both among members and between Cromwell and Parliament.