This late-fourteenth-century English romance in mainly alliterative verse by an unknown author, writing in the dialect of somewhere in the North Midlands, is the best chivalric romance in English, a work of extraordinary richness and complexity. It is, nevertheless, built on a simple basic story (essentially of a folkloric type), the testing of the young Gawain, who is presented as the exemplar of Christian knighthood in the court of King Arthur. The fascination of Sir Gawain and the Green Knight is the way in which this clear story line and the conventional topics of romance narrative – treated here with great originality – are enriched by a deep moral concern (that does not deny a certain element of comedy) and a passionate concern for chivalric and Christian values. However, while never cynical, the poem is often remarkably ambiguous, and it is therefore no surprise that critical readings have multiplied in modern times and that their interpretations have often disagreed.

The general outline of the story – a threatening challenge to the hero to exchange a blow for a blow – would have been familiar to the first audience of Sir Gawain and the Green Knight; it is an ancient story structure which has been repeatedly reworked. The earliest version is a wild Irish tale first written down about 1100; later the story was used a number of times by various authors of French Arthurian romance. So the audience would have known something of the beheading game as a chivalric adventure and a test of bravery, in which the hero survives. The character of Gawain would also have been known, for he plays a prominent part as a great knight in a number of romances. But although this preliminary knowledge may be taken for granted, the Gawain-poet puts his own typically complex and highly original twist on both the character and the story.

Having entered into the beheading game with the Green Knight in the first fitt of Sir Gawain and the Green Knight, Gawain must keep his word to seek the Green Chapel for the return blow. The account of Gawain's arming as he prepares for this quest is given an important turn by describing on the outside of Gawain's shield a pentangle and on the inside a painted image of the Blessed Virgin Mary, which encouraged the knight in battle whenever he looked at it.