On 24th April 1536, Henry VIII approved the setting up of two commissions of oyer and terminer by Sir Thomas Audley, his Lord Chancellor and Thomas Cromwell’s right hand man.
‘Oyer and terminer’ comes from the French ‘to hear and to determine’ and denotes a legal commission formed to investigate and prosecute serious criminal offences, such as treason, committed in a particular county. A grand jury in the county would first investigate the alleged offence and then approve a bill of indictment, if there was sufficient evidence. The case would then go on to the commission of oyer and terminer, the court with jurisdiction to try the offence(s). In this case, the commissions were set up to investigate crimes committed in the counties of Middlesex and Kent. Just eight days later, Anne and George Boleyn were arrested for crimes committed in those two counties.
You can read more about these commissions in my article 24 April 1536 – The Legal Machinery is Set Up.