Geoffrey Chaucer's The Canterbury Tales is a story about a group of characters who travel from London to the shrine of the martyr Thomas Becket on a pilgrimage. Written in the fourteenth century, this narrative poem has maintained its appeal because of the detailed portrait it offers of so many different kinds of people from the Middle Ages. It is also the first major literary work to be written in English, although most people wouldn't be able to read it in its original form, Middle English.

Chaucer's realism in the prologue is based on his use of satire. Satire is the act of using humor to expose a weakness or problem in society. Chaucer's use of satire lends a realism to the poem that most works of his time did not engage in.

One of the most realistically drawn characters is the Pardoner. The Pardoner travels from church to church carrying with him fake religious “relics.” He charges unsuspecting parishioners money to view these relics, which really consist of a pillowcase (supposedly Mary's veil), a piece of ordinary fabric (supposedly a piece of Saint Peter's sail), and a jar of pig bones (supposedly the remains of an unnamed saint). He is so successful that:

he in one day got himself more money

than the parson got in two months

Chaucer's realism lies in his depiction of a church official as greedy and dishonest, making much more money through deceit than the honest parson could make.

Several other characters in the prologue are also satirized in a realistic fashion, among them the Doctor, Monk, Friar, Merchant, and Miller. 

What elements of realism are in Chaucer's "Prologue" to The Canterbury Tales?

With Realism as a representation of details from contemporary life, Chaucer's The Canterbury Tales is, indeed, realistic. 

• Chaucer's unprecedented use of the vernacular rather than Latin or French, as was hitherto employed in literature, provides much realistic detail and reflects the life of the pilgrims of the time. 
• Moreover, his presentation of an extensive view of society is a veritable tableau of fourteenth-century England.
• In the "General Prologue," Chaucer's very subject matter--a pilgrimage--is certainly realistic as religious pilgrimages were customary.

Then do folk long to go on pilgrimage,
And palmers to go seeking out strange strands,

• Details appertaining to the historical setting of the time are present as, for example, there is an allusion to the Black Plague and Thomas a Becket, who was martyred at Canterbury:

...they to Canterburywend,
The holy blessed martyr there to seek
Who helped them when they lay so ill and weak

• Finally, Chaucer promises to provide realistic descriptions of the pilgrims.

To inform you of the state of every one....
And who they were, and what was their degree,
And also what array they all were in;