Geoffrey Chaucer's (d. 1400) Miller's Tale, part of the late fourteenth-century Canterbury Tales, introduces Nicholas, a poor arts scholar at Oxford, boarding with a rich carpenter, who uses astrology to predict various events in return for cash from local people. Chaucer's Nicholas is, of course, a charlatan – who cons local people into paying him money for his spurious predictions about all manner of future events, including the weather. But how credible is such a character – learned (or seemingly so) in the predictive arts and using that knowledge for financial gain – in the late medieval university town?

Chaucer was probably depicting a caricature of a known figure in late medieval Oxford. In the first place, we know that Chaucer had ties to Oxford University. His neighbour in London, Ralph Strode (d. 1387), was a graduate of Merton College – one of the prime centres of astrological learning in medieval Europe. Furthermore, Lewis (c. 1380–c. 1403), his son or godson, for whom he wrote his Treatise on the Astrolabe, was possibly sent to Oxford, although the evidence for this is by no means definitive. It seems that knowledge and possession of predictive methods could be an advantage to poor scholars, as the ability to prognosticate offered the potential for financial gain as well as prestige within the local community – whether cynically or not.

Manuscript evidence demonstrates that onomantic texts were included with writings on what can be reconstructed of the curriculum of the Faculty of Arts at Oxford University. As well as this, onomancies are present in several manuscripts that can be placed at particular college libraries in medieval Oxford. There are several possible reasons for this inclusion with items on the curriculum of the Liberal Arts and in manuscripts intended for college libraries.