This thesis concentrates on the visit of the itinerant justices to Oxfordshire in January 1261, an event that occurred at a crucial juncture in the crisis and civil war of 1258-67. The surviving eyre roll's contents provide a valuable insight into the reaction in the shires to the recent demise of the baronial council. The extent of the justices' enforcement of the baronial reforms is a fundamental issue addressed by this study. Evidence of the impact of the reforms and the subsequent civil war upon the profits of both the 1261 and 1267 visitations is examined against the background of a wider discussion concerning the revenue levels generated by all of Oxfordshire's eyres between 1218-85. How much support for the baronial regime existed amongst the county's knightly class is a question also considered by this study. Basing itself on the grand assize jurors of 1261, the chapter attempts to explore the reasons for a knight's choice of political allegiance. The study examines the breadth of criminal business that fell within the eyre's jurisdiction before focusing on the efficiency of the county's law enforcement system in 1261. An analysis of the evidence for an increase in the levels of reported homicides in Oxfordshire between 1235 and 1285 is followed by a discussion on the effects of the Barons' War on the county's reported homicide rates. The thesis considers the various civil actions featuring in the 1261 roll before attempting to establish the social composition of those actively involved in litigation. There is also a comparative analysis of the civil pleas heard by the itinerant justices in 1241, 1261 and 1285 to determine whether there any significant trends in the types of actions can be identified. Finally, this thesis provides a full transcription and indexes of the contents of the roll itself.