______ is considered Geoffrey Chaucer's masterpiece.

The Canterbury Tales is a collection of stories by Geoffrey Chaucer that was first published in 1400.

His other notable works-
- 'Troilus and Criseyde',
- 'The Parlement of Foules',
- 'The Pardoner’s Tale',
- 'The Miller’s Tale',
- 'The Friar’s Tale',
- 'The Nun’s Priest’s Tale',
- 'The Clerk’s Tale',
- 'The Man of Law’s Tale',
- 'The Franklin’s Tale'.

N.B: Troilus and Cressida is a tragedy by William Shakespeare.

Source: Britannica.com