Troilus and Criseyde, Chaucer’s greatest single achievement, is one of the finest narrative poems in the English language. Set during the siege of Troy, it tells how Troilus, son of King Priam, falls in love for the first time with a beautiful widow, Criseyde. Aided by her uncle, Pandarus, Troilus becomes Criseyde’s lover, only to lose her to the Greek leader Diomede. For its first readers Troilus and Criseyde was at once old and new, for although the tale of Criseyde’s infidelity had first been told centuries before in continental sources and was well known in England, this is the focus of only the later part of Chaucer’s narrative, where the familiar story of the love-affair’s end is prefaced …
Windeatt, B A. "Troilus and Criseyde". The Literary Encyclopedia. First published 26 November 2009; last revised 30 November -1.
[http://www.litencyc.com/php/sworks.php?rec=true&UID=8472, accessed 25 April 2015.]