Various

The Commission (of the Peace) gave Justices of the Peace the power to try offences in their courts of Quarter Sessions, appointed them to conserve the peace within a stated area, and to enquire on the oaths of "good and lawfull men" into "all manner of poisonings, enchantments, forestallings, disturbances, abuses of weights and measures" and many other things, and to "chastise and punish" anyone who had offended against laws made in order to keep the peace.

The Custos Rotulorum (Keeper of the Rolls) was responsible for the care of the county records. Appointed (since the fourteenth century) in the Commission of the Peace, he was a leading justice, unpaid and holding the post for life; and from the seventeenth century usually also holding the office of Lord Lieutenant of the county. His Deputy was the Clerk of the Peace who was in practice the actual keeper of the records, and who drew up, registered and oversaw the storage of the records.

The court case between the Duke of Westminster as Custos Rotulorum of the County of London and the Duke of Bedford as Custos Rotulorum of the County of Middlesex concerned the custody of quarter sessions records relating to those parts of Middlesex which were moved into the new County of London. The Local Government Act of 1888 had given the Middlesex Sessions House at Clerkenwell Green to the new County of London. As part of their vacating of the premises, the Middlesex Clerk of the Peace removed all court records to the Middlesex Guildhall in Westminster. The Duke of Westminster argued that the records should be divided between the two counties, so that records relating to those parts of Middlesex now in London should be handed over to the custody of London County Council. The judgement was that the records created in what was Middlesex at the time should stay in Middlesex, despite later changes of administrative boundary. A full report of the case and the reasoning behind the judgement can be found in The Times newspaper for December 19 1899.