This thesis seeks to enter into both a long running debate and a new field of research: firstly, the debate over the primary determination of the historical process in the transition from feudal to capitalist production and productive relations; and secondly, the possible relationship between English late medieval small towns and that process. Previous studies of small towns have been limited by the surviving evidence for this type of settlement, and have mainly concentrated on a narrow range of sources for the pre1348 period. The remarkable survival of a variety of sources for the small town of Lydd on Romney Marsh in Kent - probably a legacy of its Cinque Port heritage - has enabled this thesis to be the first to study an English small town in any great depth, and also during the period of agrarian capitalisation and the expansion of rural industry from the middle of the fifteenth century. The broad demographic, economic and governmental relations as they became manifest across the period c. 1450-1550 are analysed before focusing on three lists of names of social and political significance as they had come to be in 1528 after substantial structural changes had already taken place. The analysis then follows the process of structural change post-1528. The conclusion of this thesis is that between 1450 and 1550 the social formation of Lydd was transformed primarily through the determination of class-struggle in the context of the declining income of feudal lordship leading to the development of competitive rents and the formation of a new class of agrarian bourgeois. This class in a mutual relationship with feudal lordships had been instrumental as manorial farmers and officials in expropriating a densely populated parish of its small customary holdings that had previously served to support the household economies of a broad base of petty traders, artisans and fishermen. These initial expropriations ensured a developing symbiosis between larger commercial agrarian units and expanding rural industry in the Weald of Kent, providing for the emergence of capitalist relations. This ensured both greater rents for landowners and greater profits for big leaseholders. However, these structural changes are therefore implicated in the dearth of the 1520s and subsequent crises because of the increasing dependence and impoverishment of previously independent producers. The small town structures in both areas ensured that petty commodity production and trading relations were already in place upon which the process of expropriation could capitalise, and that the development of oligarchy in Lydd in particular fed off this growing wealth, and in turn facilitated increased capitalisation.