The Prologue to the Canterbury Tales acts as an explanation and an introduction to the Tales, and it allows Geoffrey Chaucer to arrange and establish the hierarchy of the pilgrims.
Chaucer uses the Prologue also to include what is called "estate satire." This is a satire of the abuses that occur within the three traditional estates, especially the clergy. One member of the Church that Chaucer ridicules is the Friar, the "finest beggar of his house." He begs from the wealthiest people in his town and makes a good sum of money; however, instead of giving the money to the poor or to the Church, the friar keeps it for himself. Chaucer remarks satirically, "This was surely a shining pearl/Of a friar!" (214-215).
In addition to satirizing the vanity and greed of the clergy, Chaucer includes the intellectuals and the middle class as well as parodying himself with a pilgrim named "Geffrey," who is a weak storyteller. Thus, he establishes a playful tone as well as a social one as the pilgrims agree to share tales on the long pilgrimage.