This work explores the development of the Anglo-Norman landed community in Essex and analyses the role of the Crown in the county's contemporary affairs. It covers a period of conquest, settlement, civil war and strengthening royal government. The assessment of the role of the Crown primarily focuses upon the relationship between the king and local landowners. It also concentrates on the maintenance and extension of royal rights, the exploitation of royal justice and forest law, the promotion and retention of peace in the county, and the development and use of royal demesne. Analysis of a community relies upon defining a local group, proving their interest in a locale and subsequently demonstrating community-linked behaviour. Such proof relies upon the use of a number of indices, some of which are drawn from later concepts of County Communities (such as participation in local government and collective identity). Other factors owe their origin to wider anthropological theories (e.g. local custom, familial ties and frequent contact between subjects). The thesis makes use of the principal primary sources for the period (Domesday, Cartae Baronum, monastic chronicles, the Pipe Rolls and extant royal, baronial and ecclesiastical acta). Owing to the greater number of surviving primary documents after 1135, it is easier to assess community ties after that date. A wide range of secondary sources also exists, many of which have been utilised and, in some cases, expanded upon. This research has demonstrated that a community was evident among both the tenants-in-chief and sub-tenants of Essex from the reign of William I and that it advanced during the century that followed his death. This was partially due to the immense tenurial stability of the county at that time. It also shows that royal influence in the county was at a consistently high level, where the Crown normally had more land in Essex than any other individual. This ensured that Essex was one of the most peaceful and prosperous English counties between the accession of William the Conqueror and the death of Henry II.