This is a study of a local society and its interaction with central government observed through routine administrative systems. Although Northumberland has been the focus of detailed investigation during the late middle ages, a gap in scholarship remains for much of the first half of the fifteenth century. As England’s most northerly county, work on the relationship between provincial society, peripheries of the realm and the crown is critical to this study. This research tests assumptions that Northumberland was feudal, lawless, distant and difficult for the crown to administer. The research consists of two parts: the first is an evaluation of social structure; the second explores the administrative machine. It opens with a survey of feudal tenure. Chapter two examines the wealth of resident landholders. Chapter three outlines the genealogies of landed society and their relationship to one another as a ‘county community’. Chapter four expands on family connections to incorporate the bond of spiritual kinship. Chapter five charts the scope of social networks disclosed though the management of property, personal affairs and dispute. Chapter six considers the inquisitions post mortem (IPM) process and the impact of distance. Chapter seven discusses jurors and their place in county society. Original contributions to knowledge are made in a number of areas. The theme of spiritual kinship has not been developed in any county study of this period. Additional information concerning the county return for the 1435 subsidy on land is provided, which has previously been overlooked. The location of a copy of the escheator’s oath created in response to a statute of 1429, which has not been captured in recent studies, resolves the current ambiguity concerning the statutory requirement of an indented inquisition return.