This chapter takes an in-depth look at the corpus of manuscripts that contain onomantic devices and were produced between the years 1150 and 1500 in Britain. It will analyse the ‘footsteps in the sand’ left behind in these manuscripts in the form of textual variations, attributions and signs of use, to build a fuller picture of onomancy in the later Middle Ages. The corpus of sixty-five manuscripts containing at least one whole or partial onomantic device produced in late medieval Britain includes two manuscripts which once contained onomancies but no longer do, as evidenced by their contents lists, and a missing manuscript containing a ‘Sphere’ whose contents are listed in the library catalogue of the Austin Friars at York (now Dublin, Trinity College Library, MS 359, fols. 5r–48v), produced in 1382. Several of the manuscripts contain multiple onomancies, which means that the total number of devices is more than the total number of manuscripts. However, not all of the devices are complete: some are devoid of diagrams, others of texts, and some are unfinished.

The manuscripts in which onomantic devices are located vary widely, from larger reference works to smaller books intended for everyday use; from books containing works of natural philosophy, astrology and medicine to the commonplace books of householders containing practical medicine; and to the manuscripts of university scholars, compendia of monks and the luxury books of the aristocracy and gentry. More than half of this corpus, thirty-seven manuscripts, can be confidently assigned to the fifteenth century. In contrast, just seven were written in the thirteenth century, and three in the later twelfth century. Does this mean, then, that onomancy became more popular as the Middle Ages came to a close? The simple answer is ‘possibly’, because there are a number of important factors to bear in mind here.

First, the number of onomancies that survive is in no way indicative of the original number that were produced: probably many more were copied. To estimate just how many more would, of course, be impossible.