"The Wife of Bath's Tale," from Chaucer's "Canterbury Tales," is an exemplum, a story that disguises a polemic with serious political and religious undertones as a farcical portrait of a bawdy woman. The subtext of the story is that the Wife is deeply heretical for insisting on her rights in the face of official oppression from the religious and secular authorities of the day.
The tale of the Wife of Bath opens with a prologue that's longer than the tale itself. In the prologue, the Wife admits that she's "had five husbands by the church door." That is, she's been married five times, which was unusual and frowned upon by the 14th-century church. Her husbands keep dying, and she sometimes finds a new husband at the last one's funeral. She claims to trust experience over the authority of the church or scripture and at one point almost openly disagrees with a stated opinion of Jesus. Her tale is of an old hag in the time of King Arthur who becomes beautiful because she "gained sovereignty" over her husband.
The Wife of Bath is a scathing critique of the medieval church's depiction of women as subordinate and inherently sinful. As a farcical caricature, the Wife is free to make several points against the orthodoxy of the time that would otherwise have been openly heretical. Her tale was Chaucer's way of criticizing both patriarchy and prudishness.