Morgan le Fay's fidelity-test drinking rule

Morgan le Fay's fidelity-test drinking rule is a purported trial of marital faithfulness, enacted through a gold-mounted horn: a woman who is true to her husband can drink from it, while a woman who is false spills the drink. Its arrival at King Mark's court turns a magical claim into a public accusation against Queen Isoud and other women, but the barons refuse to accept the result as grounds for punishment.

The Horn and Its Test

The rule is presented through a horn carried by a knight sent from Morgan le Fay to King Arthur. The horn is harnessed with gold and said to have a fixed virtue: a faithful wife or gentlewoman can drink from it peaceably, whereas an unfaithful one spills the drink. The account offers no independent means of verifying that claim; its authority rests on the horn's supposed magical power and on the result of each woman's attempt.

How the Test Reaches King Mark

Sir Lamorak compels the messenger to explain why he carries the horn. He then directs him to take it to King Mark, explicitly framing the test as an insult to Sir Tristram: Mark is to use it to test his lady. The messenger delivers the horn and describes its stated virtue, and Mark makes Queen Isoud drink from it along with a hundred ladies.

The Result and Its Limits

Only four of the women who drink do so without spilling. King Mark treats the result as a grave affront and swears that Queen Isoud and the other women should be burned. The test thus produces an apparent verdict, but not a settled judgment: the barons gather and declare that they will not allow the women to be burned because of a horn made by sorcery.

Conflict and Narrative Significance

The barons condemn the instrument as the work of a sorceress and witch, saying that it has done no good and has instead caused strife and debate. They also connect Morgan le Fay's device with hostility toward true lovers, and several knights vow to confront her if they meet her. The episode exposes the danger of treating a magical ordeal as conclusive proof: the horn's claimed power creates public suspicion and threatened punishment, while the court's refusal to trust it prevents that accusation from becoming an accepted sentence.