The most revolutionary changes in the business of the House of Lords during the early Stuart period occurred in its judicial activities. A treatise on the judicature of the House, written in or about the year 1630, is often ascribed to John Selden, but it was actually composed by Henry Elsyng, clerk of the parliaments. As an observer of many of the processes he describes, his account is of particular value. He analyzed the judicature of the House in the following categories: (1) trying peers for felonies or capital offenses; (2) making judgments against delinquents for capital crimes or misdemeanors on complaint of the king, the Commons, or private persons; (3) reversing erroneous judgments in parliament or in King's Bench; (4) deciding suits long depending in other courts; (5) hearing complaints of particular persons; and (6) setting at liberty members or their servants and staying proceedings at common law against them during time of parliament.1 In Elizabeth's reign and the years 1603 to 1621, the House of Lords judged no cases on impeachment. It heard a few cases of error from King's Bench but no appeals from other courts. It accepted no cases of the first instance except those that affected its own privileges. In 1621 and the years following, however, impeachment cases at times became the chief business of the House.2 Cases in error, which earlier could have been counted on the fingers of one hand, rose to number in the hundreds. The House heard appeals or reheard cases earlier heard or still pending in Chancery, the Exchequer, the Court of Requests, Star Chamber, the Court of High Commission, and other ecclesiastical courts.3 It accepted a wide variety of cases of the first instance. Cases of privilege greatly multiplied. Judicial hearings occupied a major portion of the Lords' time. The high court of parliament became a working reality.