The Lord Chancellor is one of the most ancient offices of state, dating back many centuries. The Lord Chancellor is appointed by the Monarch on the advice of the Prime Minister and is a senior member of the Cabinet. They head the Ministry of Justice as the Secretary of State for Justice. Previously the Lord Chancellor also acted as Speaker of the House of Lords and therefore sat on the Woolsack. The Lord Chancellor was also head of the judiciary and the senior judge of the House of Lords in its judicial capacity. However, under the Constitutional Reform Act 2005, the Lord Chancellor ceased to be the Speaker of the Lords, and was replaced by the Lord Speaker. In addition, the Lord Chief Justice is now head of the judiciary, and the Lord Chancellor may no longer sit as a judge.