Sir Gawain and the Green Knight

This anonymous 14th-century Middle English poem opens at King Arthur's Camelot on New Year's Day, when a gigantic Green Knight rides into the hall and proposes a strange game: any knight may strike him one blow with his axe, so long as that knight agrees to seek him out in a year and receive an identical blow in return.

Sir Gawain accepts and beheads the stranger in a single stroke — only for the Green Knight to calmly pick up his own severed head, remind Gawain of their bargain, and ride away.

A year later, Gawain travels to keep his word and is welcomed at a remote castle by its lord, who proposes a game of his own: each day he will hunt in the woods while Gawain stays behind, and at nightfall the two will exchange whatever each has won.

On three successive days, the lord's wife tries to seduce Gawain, who fends her off with courtesy while accepting only kisses and, on the last day, a green silk girdle she claims will protect him from harm — a gift he conceals from his host.

When Gawain finally faces the Green Knight's return blow at the Green Chapel, the truth of the girdle, the castle, and the whole test of his honesty and chivalry comes due. A foundational work of Arthurian romance, the poem is prized for its intricate structure, its moral ambiguity, and its unflinching interrogation of what perfect knighthood actually costs.