Late Medieval Calendars and the Folded Almanac
Medieval calendars in the compotus manuscripts of the early middle ages included basic astronomical information concerning the cycles of the Sun and the Moon. The next important development in the Western calendar began in the wake of the European encounter with Islam in the tenth and eleventh centuries, when knowledge of Greek, Roman, and Arabic astronomy began to enter the learned Latin tradition. Those developments introduced astronomy and astrology to the West over several centuries. In this sense, the story of calendars in the Latin West is one part of the larger history of the transformation of science in the high middle ages.8
The adoption of this rich and scientifically rigorous discourse into Western Europe was initiated, in part, by the translation of key Arabic texts and Arabic translations of Greek texts into Latin. These included Ptolemy’s Almagest and Tetrabiblos. Calendars in later medieval England took new shapes partly because of the spread of astrological literacy that accompanied—that was indeed inextricable from—the increase of knowledge concerning classical, Ptolemaic, and Arabic astronomy in the West. By the middle of the fourteenth century, astrology had become “a standard part of the curriculum of most European universities” with particularly renowned programs in Italian and Spanish Universities.9 In England, key figures in this history include Robert Grosseteste (c. 1175-1253) and Roger Bacon (c. 1219-c. 1292) in the thirteenth century, and Richard of Wallingford (1292-1336) in the fourteenth, who produced compotus calendars with astrological information for English latitudes.10 These and other later calendars mingled religious, medical, astronomical, and astrological information.
An important moment in the history of the calendar occurred in the fourteenth century, when a calendar calculated by Walter Odington for the years 1282-1367 was about to expire.11 In the 1380s, two English Friars associated with Oxford—the Carmelite Nicholas of Lynn (fl. 1386) and the Franciscan John Somer (fl. 1386)—wrote separate calendars for England for the four Metonic cycles that covered the years from 1386 to 1462.12 The kalendaria of John Somer and Nicholas of Lynn marked, as Linne Mooney has noted, “the beginning of the calendar boom...in manuscript,” and they also provided a model followed by many English calendars into the sixteenth century.13 These calendars were on the one hand aimed for users with high status and educational achievement: clerics, physicians, and the educated elite. The calendars’ patrons were educated lay royalty: Joan, Princess of Wales, commissioned Somer’s calendar, and John of Gaunt was the patron for the calendar of Nicholas of Lynn.14 It was perhaps the royal encouragement of astrology, and its association with glamorous court culture, that spurred increased interest among the aristocracy and “literate middle classes” in calendars and astrology.13
The Somer and Lynn kalendaria survive in various manuscripts, but it is their frequent appearance in one particular format that is of the greatest interest for the later history of the almanac: the folding medical almanacs that first appear in the late fourteenth century. J. Gumbert’s catalog of these artifacts lists sixty-six survivals; almost half of these (twenty-nine) were created for England. These books have been variously named girdle books, “physician’s vade mecum,” “physician’s folding almanacs,” and “bat books,” the latter Gumbert’s whimsical nod to the way they unfold, like bat wings.1 Hilary Carey’s more neutral and descriptive term, folded almanacs, distinguishes these manuscripts from other girdle books and registers the probability that they were used by a range of professionals and medical practitioners, not only physicians.18 Like later almanacs and writing tables, these calendars are designed for portability. Not only do they fold ingeniously to a pleasingly small size, but many surviving examples include leather cases and loops for attaching to belts; Bodleian Ms. Ashmole 6 is a representative example.19 The densely written, intricately folded pages of these almanacs include a wealth of information designed to support medical, astrological, and religious needs. Most importantly for the later history of the calendar, as Carey has written, “The folded almanac can be seen as the progenitor of all later compact-form diaries, calendars, and electronic organizers.”20
