Who wrote “The Book of the Duchess” ?

Geoffrey Chaucer What's the author of The Book of the Duchess”.
-That poem of more than 1,300 lines, probably written in late 1369 or early 1370, is an elegy for Blanche, duchess of Lancaster, John of Gaunt’s first wife, who died of plague in September 1369.

-He was the outstanding English poet before Shakespeare and “the first finder of our language. - The Canterbury Tales ranks as one of the greatest poetic works in English.

He also wrote:
-The Parlement of Foules,
-Troilus and Criseyde, and
-The Canterbury Tales.

Source:Britannica.com