Much of the English legal system was developed in and around Westminster Hall. Since medieval times the Courts of Kings Bench and Exchequer sat in simple wooden enclosures in the south end of Westminster Hall. At the west end sat the Common Pleas and other courts were in adjacent buildings. These enclosures were removed for functions requiring the entire use of the Hall, such as state trials.
During the 17th Century Trials in Westminster Hall included that of Guy Fawkes and the Gunpowder Plot Conspirators in 1606. Later came the trial of the Earl of Strafford in 1641, the trial of King Charles I in 1649 and the trial of the Seven Bishops in 1688.
In the 18th Century the impeachment of Warren Hastings (1788-95) was the longest trial in history and although eventually cleared, the trial ruined him financially.
The courts were cleared from the Hall for the last time in 1821 in preparation for the coronation banquet of King George IV. The Prime Minister Lord Liverpool thought the Hall should remain free of internal buildings. The Law courts were then housed in a new building by Sir John Soane to the west of Westminster Hall.