Historians of the medieval English Church have long known the dates of someofficial mandates that supposedly instituted the celebration of new feasts andchanged the instructions for celebrating established ones. Unfortunately, however, thatofficial chronology does not provide much guidance for dating liturgical manuscripts.Indeed, there is surprisingly little correlation between the apparent dates of most Sarumbreviaries and the extent to which they have implemented the mandates. For a fewfeasts one can find manuscripts that actually predate the mandates. The most obviousexample is the July 26 feast of St Anne, conspicuously present with full offices andproper lessons in the original Sanctorales of at least two Sarum breviaries from the firsthalf of the fourteenth century, BL Stowe 12 and Edinburgh University 26, althoughit was not officially mandated for English observance until 1382–3. Stowe and a fewother Sarum manuscripts also seem to have anticipated the 1328–9 decree ordering thecelebration of the Conception of the Virgin.

In most cases, however, the contents of the manuscripts lag far behind the recordeddates of the mandates that one might expect to have governed them. Studying theorigins of the Feast of Corpus Christi in England, for example, Miri Rubin founda gap of over half a century between the 1264 decree that established this feast andthe first clear evidence of its adoption anywhere in England. Studying the major newfeasts of the later fifteenth century, R. W. Pfaff found that the Visitation, althoughinstituted in 1389 by Pope Boniface IX and mandated in 1441 by the Council of Basel,did not ordinarily appear in English liturgical manuscripts until after 1475; amongSarum breviaries, he identified only three possible exceptions (Royal 2. A. XII, Bute,and the Brigittine supplement to Royal 2. A. XIV) – all three written on the Continentor under French influence, or both. My own work on Sarum breviaries suggests thatsimilarly widespread delays occurred with regard to the five saints’ feasts mandated by Archbishop Chichele in 1415 and 1416 (David, Chad, Winefride, and the feast day andTranslation of John of Beverley). Although the first three had been ordered as early as1398, by Archbishop Roger Walden, these saints are absent even from the Kalendarsof most Sarum breviaries produced in the first few decades of the fifteenth century,including Chicheles own copy, and they are only sporadically included in Sanctoralesuntil 1435 or later.