 During the 15th century , the traditional superiority of the common law courts was challenged by ecclesiastical courts and the equitable jurisdiction of the Lord Chancellor , exercised through the Court of Chancery . These courts were more attractive to the common lawyers because of their informality and the simple method used to arrest defendants . The bills of complaint and subpoena used by the Chancery made court procedure far faster , and from 1460 to 1540 there was a steep decline in the number of cases in the common law courts , coinciding with a sharp increase in cases in the newer courts . This loss of business was quickly recognised by the King 's Bench , which was urged by Fairfax J in 1501 to develop new remedies so that " subpoenas would not be used as often as they are at present " . From 1500 the King 's Bench began reforming to increase its business and jurisdiction , with the tide finally turning in their favour by 1550 . The King 's Bench significantly reformed its mode of practice in response , and one of the developments was the Bill of Middlesex . 
