 As a result of reforming actions such as the Bill of Middlesex , the Common Pleas became increasingly conservative and resistant to King 's Bench changes because of the impact they had on the business of the Common Pleas . This was best emphasised by Slade 's Case , a struggle between the old and new forms of suing for breach of contract ; although an equilibrium between the common law courts was finally reached , it eventually led to their dissolution with the Supreme Court of Judicature Act 1873 , and merger into a single High Court of Justice . 
