Any attempt to follow in detail the history of the Justices of the Peace, and the powers resident in them, is beyond the scope of the present work; this task has already been often and ably performed.[39] It is impossible, however, to divorce the functions of the Justice from those of the Constable; the story of the evolution of the latter is so dovetailed into the history of the former, the two are so closely allied in their mutual relationship of master and servant, that some reference must here and elsewhere be made to the office of the Justice, a functionary who claims a considerable share of attention in any enquiry that deals with police in the full interpretation of the word, because the executive power vested in a Justice as Peace Officer is antecedent to, and on the whole more important than, the judicial authority attaching to him as Magistrate: in other words, he must be considered as a policeman first, and as a judge afterwards. The origin of the Justice's office is by no means obscure. Towards the close of the twelfth century (1195), by a proclamation of Richard I.,[40] Knights were appointed to see that all males over the age of fifteen years were "sworn to the King" by taking a solemn oath to maintain the peace: after fifty years or so had elapsed (1253) these Knights had become Peace Wardens or Conservators, who again, continually undergoing a process of development as the importance of the Sheriffs dwindled, were eventually invested with judicial powers, and were then known as Justices of the Peace.