In 1253 the ‘lesser commune’ of Oxford directed a petition to Henry III with complaints against the ‘magnates’ there who were misusing their powers over taxation and commerce and otherwise abusing their authority. After examining the persons and the complaints, this article concludes that the petition is credible and its complaints consistent with the concerns of the baronial reform movement. But after 1265 the old oligarchy was able to reassert its local dominance. The article contributes to the ‘pre-history’ of the reform movement and to the role of towns in it, both of which are still largely unexplored.