My next step in this research was to read The Testament of Cresseid, written by Robert Henryson in the late 15th century. This poem is essentially 500-year-old fanfiction, imagining an untimely death for Criseyde in which she is struck with leprosy by the gods after blaming them for her rejections at the hands of Troilus and Diomedes.
Like many other “Chaucerian” works of dubious origin, the Testament was often published along with Chaucer’s own Troilus and Criseyde in early editions of Chaucer’s works, including the 1721 Urry edition.

The introduction to the Testament in the Urry Chaucer (pictured above) demonstrates that scholars were aware that this was not Chaucer’s own writing; many other spurious works (such as The Plowman’s Tale) were published repeatedly under Chaucer’s name.