Across the medieval period, the administrations of Church and State were heavily intertwined, both in terms of procedure and personnel. Consequently, records relating to the English Church survive not only in the archives of the various dioceses and archdioceses, usually in county or regional archives, but also throughout the collections at TNA, the successor to the Public Record Office and archive for records created by and for the English (and later British) royal governments from the eleventh century onwards. Many of these appear in series already well known to historians: the vast rolls of Chancery contain thousands of examples of activities pertaining to church administration, from royal presentations to benefices, to the granting and collection of clerical taxation, while the Ancient Petitions (SC 8) and Ancient Correspondence (SC 1) are littered with requests and letters from clerics of all ranks. Many of these documents stemmed from, or led to, correspondence also recorded in the episcopal and archiepiscopal registers, often allowing events to be viewed from both sides, while others can provide additional stages in administrative processes, or record business never included in even the fullest and most detailed episcopal register or archive.

But there are also certain series within TNA's collections devoted specifically to the direct administrative interaction between Church and State. One such series, which has attracted relatively little attention from historians, is the Significations of Excommunication (C 85), which record attempts by the Church to employ the royal administrative machinery against its recalcitrant members. The process of excommunication was long-established, and its use lies well beyond the scope of this paper. It remained the ultimate sanction available to the medieval religious authorities, as it effectively severed individuals or groups from all contact with their church and, at least in theory, wider society. Not only could excommunicates no longer attend church services, but they could not be buried in holy ground, could not take part in other church or social activities, and even their own families were expected to shun them. The reasons behind an excommunication could be many and varied, but for all its power and influence, the medieval Church's ability to enforce its sanctions was limited.