From 1374 Chaucer worked as controller of customs on wool in the port of London, but between 1366 and 1378 he made a number of trips abroad on official business, including two trips to Italy in 1372-3 and 1378. The influence of Chaucer's encounter with Italian literature is felt in the poems he wrote in the late 1370's and early 1380s - The House of Fame, The Parliament of Fowls and a version of The Knight's Tale - and finds its fullest expression in Troilus and Criseyde.

In 1386 Chaucer was member of parliament for Kent, but in the same year he resigned his customs post, although in 1389 he was appointed Clerk of the King's Works (resigning in 1391). After finishing Troilus and his translation into English prose of Boethius' De consolatione philosophiae, Chaucer started his Legend of Good Women. In the 1390s he worked on his most ambitious project, The Canterbury Tales, which remained unfinished at his death. In 1399 Chaucer leased a house in the precincts of Westminster Abbey but died in 1400 and was buried in the Abbey.