Medieval romances are rooted in the tradition of Greek romances:
The stories, often about faithful lovers separated and reunited after perilous adventures, were carried on in the oral tradition.
Sir Gawain and the Green Knight is written in a style similar to the stories of King Arthur and the Knights of the Round Table.
The early chronicle accounts of Arthur all contain the elements of love, mystery, adventure, and psychology that have now come to be associated with romance.
These stories often dealt with chivalry (the most important piece of this tale), which is:
Heroic warfare [which included] chivalry: standards of conduct especially when dealing [with] someone on your same level.
Chivalry is also defined as,
The sum of the ideal qualifications of a knight, including courtesy, generosity, valor, and dexterity in arms.
They also can address themes of courtly love, bravery, a knight's prowess in battle, a dedication to the Virgin Mary, and psychology, as well as including the presence of the supernatural (things beyond the natural realm). While other stories (such as the epic tale Beowulf) generally have tragic endings, medieval romances often have favorable ones.
This story begins at Christmastide, when the mysterious Green Knight appears at Arthur's court and issues a challenge to anyone who will take it: a swing for a swing. The man who accepts his contest will have first swing at the Green Knight. Young Gawain, in a show of bravery, accepts the terms and cuts the Green Knight's head off—whereupon the Green Knight picks up his head, which (resting in the Green Knight's hands) demands that he have his opportunity with Gawain, a year from that day. This introduces the element of the supernatural.
A year later, Gawain travels to meet the Green Knight as agreed—his chivalric code demands that he keep his word. On his way he comes upon a castle where he is welcomed by Lord and Lady Bertilak. While the lord hunts each day, his lady tries to seduce Gawain, who gallantly resists. However, on the third day she gives him a belt ("girdle") that will protect him from harm. Although his code demands that he return it, fear for his life makes him keep the gift.
Valiantly, Gawain goes out on the appointed day to meet the Green Knight demanding they begin what was started a year before. With the first swing, the Knight stops himself. However, when the Green Knight positions himself for a second swing, for all Gawain's bravery and even the possession of the magical green belt, the younger man flinches at the swing, betraying his chivalric code. The Green Knight chastises Gawain and questions his reputation as a valiant knight.
Gawain pulls himself together. He promises not to move and declares:
And this much is plain:
My head, if it falls, won't talk in my hands (2282-2283).
Once more the Green Knight stands to take another swing. Rather than cutting off the young knight's head, the Knight simply nicks his neck, whereupon Gawain rises to defend himself. It is at this time that the Green Knight reveals his identity: he is Lord Bertilak. He explains that his wife's behavior was a test for Gawain. Gawain broke his code first in taking the belt and, later, in flinching. The Knight explains that Gawain "failed a little/lost good faith. . . for the love of your life" (2366, 2368).
Gawain is distraught and devastated:
Fear of your blow taught me cowardice,
Brought me to greed, took me from myself
And the goodness, the faith, that belong to knighthood.
I'm false, now, forever afraid
Of bad faith and treachery (2379-2383).
Gawain begs the Knight to forgive him and promises to try "to sin less" (2388). The Green Knight immediately does so.
While the story ends happily enough (Gawain does not die), the reader gets the sense that Gawain will never see himself in the same light. Herein lies the element of psychology—he has learned a valuable lesson that will drive him to live a more chivalric life from that point on; his failure to follow the code that guides his actions is a blow from which he will not quickly recover but will motivate him to lead a more chivalrous life.
Adventures in English Literature, Harcourt Brace Jovanovich Publishers: Orlando, 1985.