Geoffrey Chaucer is one of the most English writers of the Middle Ages and lived during a period of great religious upheaval. Chaucer's era was dominated by the Great Schism, when two men claimed to be the pope; with one residing at Rome and the other at Avignon in France. This split spilled out into politics, with European monarchs forced to take sides and, to exacerbate the problem, a third papal claimant appeared in 1409. This scandal altered the way in which ordinary people, like Chaucer, viewed the Catholic Church. The schism made the papacy seem disunited, disorganized and, above all, very corrupt.
We can see evidence of Chaucer's belief in its corruption in the General Prologue of his most famous book, The Canterbury Tales. In this section, Chaucer introduces the character of the friar and says of him:
259 For ther he was nat lyk a cloysterer
For there he was not like a cloistered monk
260 With a thredbare cope, as is a povre scoler,
With a threadbare cope, like a poor scholar,
261 But he was lyk a maister or a pope.
But he was like a master of arts or a pope.
262 Of double worstede was his semycope,
Of wide (expensive) cloth was his short cloak,
263 That rounded as a belle out of the presse.
Which was round as a bell fresh from the clothespress.
Here, we see Chaucer directly mock the wealth of the pope, or popes at this time, and also highlight an important problem with religious figures: that they had become so obsessed by material possessions that they had lost sight of what was most important: the word of God.