The trial of King Charles I, which began on 20 January 1648 and lasted four days, is described in Book X of Clarendon's History of the Rebellion. The painting depicts an incident that occured on the first day, after the President, John Bradshaw, has upbraided the King for wearing his hat (in Clarendon all the judges are wearing their hats) and the King had rejected the authority of the court. The Caption to the engraving by Claud Du Bosc, in reverse, relates the incident:
'On the first day 67 Commissioners sat, & when General Fairfaix's name was called over among the Commissioners & Judges his Lady who was among the Spectators had the courage to stand up & say aloud He has more Wit then to be here & soon after the Impeachment was read, & that expression used, In the name of all the good People of England she likewise cry'd out No nor one hundredth part of them.'
The caption also adds a further incident, not in Clarendon but depicted in the picture:
Directly following on from Lady Fairfax's expulsion 'It was remarkt, that the Gold Head dropt off from the King's Cane this day without any visible cause.' In fact the head of King Charles I's cane dropped off when he tried to interrupt John Cook, the Solicitor General, while opening the charge against him by tapping him on the shoulder.