Why does Sir Gawain cut off the Green Knight’s head?

Sir Gawain cuts off the Green Knight’s head as part of the Green Knight’s challenge to strike him anywhere with his ax and then receive the same blow in return a year later. Given the enormous size of the ax, there’s no doubt that any blow from it is likely to end in death or permanent injury. Thus, we can assume that Sir Gawain hopes to avoid facing the future blow by killing the Green Knight.

Why is the Green Knight green?

The greenness of the Green Knight connects him to wildness and nature. While King Arthur’s court represents Christian civilization, the green of the Green Knight brings the wilderness into his court, challenging its strength and honor.  In addition, the knight’s greenness can refer to rebirth. Not only does the Green Knight rise from the dead, but his absolution of Sir Gawain also is a kind of rebirth. He sends Sir Gawain back to Camelot changed but returning from apparent death.

At the end, why does the Green Knight forgive Sir Gawain?

As the Green Knight sees it, he has given Sir Gawain a succession of missed blows that accurately represent Sir Gawain upholding his end of the bargain he makes with Bertilak, and hits Gawain once gently for hiding the girdle. Thus, he views Sir Gawain as having paid off his debt. The Green Knight also considers Sir Gawain’s reason for deception, a desire to live, as something understandable and not sinful, or at least, not as sinful as succumbing to his wife’s seductions would have been. Finally, the Green Knight acknowledges that Sir Gawain has confessed all wrongdoing. With these three considerations, the Green Knight forgives Sir Gawain entirely.

Who are the old woman and the young woman at the castle?

The young woman is Sir Bertilak’s wife, whose name we never learn. Sir Gawain finds himself instantly attracted to her beauty and charming company, but she later becomes an obstacle as she tries to seduce him. The old woman, we later learn, is Morgan Le Fay, a fairy or goddess, King Arthur’s half-sister and sometimes enemy. The orchestrator of the entire predicament Sir Gawain finds himself in, she sends the Green Knight to Camelot to test the chivalry of King Arthur's Court and frighten Guinevere.

Why does Sir Gawain continue to wear the green girdle?

Sir Gawain continues to wear the green girdle as a reminder of his sin of deceiving Bertilak. Although Sir Gawain has prided himself on being the perfect Christian knight, he nevertheless succumbed to the temptation to lie in order to protect himself from the Green Knight’s blow. This incident has revealed to him how easily mortals are corrupted (“the fault and the deceit of the crabbed flesh, / how tender it is to catch stains of filth”), and states that wearing the girdle will keep his pride in check, reminding him that even he is prone to sin.