In the Morte Darthur the collapse of the Round Table is not solely caused by Launcelot and the queen's adultery nor by the rebellion of the incestuous son. Instead, that society fails because of a variety of problems related to marriage. Arthur's fertile desire produces Mordred; Guenevere's infertile body fails to produce an heir; the queen and Launcelot's relationship leads to fissures in the body politic, irritated by Lott's sons, who are Arthur's heirs apparent. Guenevere's place at the center of chivalric society persists until the end of the Morte Darthur when Mordred attempts to seize not only the kingdom and crown, but the queen's hand in marriage. Chivalric stories cease only when the queen seals her body away from men, becoming a nun, and begins her own campaign for “getting” or begetting her own “soule” (Works 1252.12). Although barren, Guenevere has a formative influence on chivalric society, essentially bringing to birth the Round Table society in the book's opening. After its fall, she ushers in its religious redemption.

When Guenevere steals away to Amesbury, she engages in such fervent repentence “that all maner of people mervayled how vertuously she was chaunged” (Works 1243.11–12). Guenevere seals herself off not only from the incestuous Mordred but from the adulterous Launcelot. In the convent she rejects her former lover and lists the effects of their adultery: “Thorow thys same man and me hath all thys warre be wrought, and the deth of the moste noblest knyghtes of the worlde; for thorow oure love that we have loved togydir ys my moste noble lorde slayne” (Works 1252.8–11).