For more than eight hundred years the liberty of St Albans existed as a zone of legal privilege. At its fullest extent, the liberty cordoned off from royal and diocesan interference the greater part of south-western Hertfordshire, an area designated as the lordship of the abbot of St Albans. After the dissolution of the monasteries, the liberty and hundred of St Albans remained in the hands of the crown and its special status survived until 1874 when its separate commission of the peace was abolished, together with the liberty, leaving only the empty title as one of two divisions within the county of Hertfordshire. Modern historians have traced the beginnings of this durable institution to the twelfth century, although their medieval predecessors, at least those who were members of the monastic community at St Albans, would have laid claim to an older origin still, at the hands of the alleged founder of the house, Offa, king of Mercia (757-96). In claiming Anglo-Saxon origins for special privilege, the monks of St Albans conformed to a familiar pattern. In the century after the Norman conquest the communities of a number of older religious foundations paraded Anglo-Saxon founders and benefactors, royal and episcopal, in defence of exceptional status. Their hopes uniformly rested on fundamentally anachronistic expectations. As Patrick Wormald has recently reiterated, the charters which support special claims to exemption are, without exception, inauthentic. But the paradigm flourished nonetheless. Why Anglo-Saxon origins should have been invoked so consistently and so erroneously is a matter which remains little understood. It is striking that so frequently claims to special liberties, particularly jurisdictional rights, were pinned on benefactors living in an era when no such privileges are supposed to have existed. The community of St Albans bid for special privilege with considerable success; their actions therefore serve as an illustration of the vitality and efficacy of Anglo-Saxon precedent as the basis for claims to legal recognition of difference after the Norman conquest. The liberty of St Albans embodied continuity real and imagined. It had a genuinely exceptional status (or series of statuses) justified as immutable and ancient by a process of periodic updating and selective amnesia. It thus illustrates a well-attested historical process. In addition to providing a historical spectacle, however, the liberty poses a methodological problem.