The Canterbury Tales were begun by Chaucer, as we have seen, about 1387, after he had completed Troilus and Criseyde and after he had begun and presumably abandoned the Legend of Good Women. It is thus the work of his latest years, though it shows no signs of age or fading power, and indeed is remarkable for its vigour and freedom and its extraordinary innovative and experimental character. It may have been that Chaucer gained this freedom from his security in the achievement of his magnum opus, Troilus and Criseyde, for there can be no doubt that the literary care lavished on that poem is of a kind quite different from what we find in the Canterbury Tales, and is designed to make it worthy of comparison with the work of the great poets of the past:

Go, litel bok, go, litel myn tragedye, Ther God thi makere yet, er that he dye, So sende myght to make in som comedye! But litel book, no makyng thow n'envie, But subgit be to alle poesye; And kis the steppes, where as thow seest pace Virgile, Ovide, Omer, Lucan, and Stace. (V. 1786-92)

The conscious regard for posterity, and for the accurate transmission and true understanding of the text (V. 1793-8), the self-conscious solemnity of the opening invocation and closing prayer of the poem, the elaborate structure and highly-wrought style, all claim a confident place for Chaucer in the pantheon of poets, and are quite exceptional in the English poetry of the Middle Ages. The Canterbury Tales are bound to suffer in comparison with Troilus because of their unfinished state, but their very incompleteness and open-endedness are part of the challenge they offer to our powers of perception and understanding. They do not show Chaucer relaxing amid the familiar furniture of his mind, but rather a spirit of innovation and experiment in which he can explore imaginative territories of the existence of which there is little hint in Troilus.