|The charters confirm or grant privileges enjoyed by the burgesses of the borough of Huntingdon. Not until the charter of 1484, however, was the town formally incorporated.
Many charters are simply confirmations of earlier ones: these were obtained from the reigning monarch in case he or she disclaimed grants made by predecesors. These charters of confirmation generally include the full texts of earlier grants. As a later confirmatory charter may include the full text of an earlier confirmatory charter, which in turn quotes in full an even earlier charter, it will be seen that the texts of many charters accrue over the years. The charter of 1205, for example, is quoted in full at least nine times (1252, 1381, 1402, 1424, 1484, 1515, 1550, 1554 and 1559). Detailed comparison of the texts of the original charters with the texts of their copies in later charters shows occasional mis-copyings, additions, and omissions, which then follow through in subsequent copies.
Strictly speaking, only the grants of 1205, 1252, 1381 and 1402, and the stray charter of 1348, are properly called charters. These five grants were addressed to leaders of society, were witnessed by various named individuals, and were then closed and sealed with the Great Seal of England. Copies of the texts were made on the Chancery's Charter Rolls, now held at the National Archives. All of the remainder are letters patent, ie. they were not sealed up, but were exposed to open view with the Great Seal pendent at the bottom, and were addressed to all the subjects of the realm. Copies of the letters patent were made on the Chancery's Patent Rolls, now held at the National Archives. The letters patent were witnessed by the King himself, rather than by named individuals, which is why the catalogue entries for the letters patent do not include witnesses' names.