In Chrétien's romance, Laudine is the ruler of the mystical Castle of Landuc located near a spring in Brocéliande Forest. Her husband Esclados guards the magical spring, which generates a huge storm when water from it is poured onto a nearby basin. Yvain's cousin Calogrenant had once done this and been attacked and beaten for it, so Yvain sets out to avenge him. Yvain mortally wounds Esclados and follows him back to the castle, where he espies Laudine and falls instantly in love with her. Though she is distraught by her husband's death, her vassals, especially her servant Lunete, talk her into marrying him so the land won't go unguarded.
Things go well for a while until Sir Gawain invites Yvain to seek chivalric adventure with him. Laudine does not want him to go, but relents when he agrees to return after a set number of days. She provides him with a magic ring that protects true lovers from bodily harm, and warns him not to be late. Yvain gets caught up in his exploits, and does not come home. Laudine sends a messenger to reclaim her ring and inform her husband he will not be allowed back. After a period of madness, Yvain engages in new adventures, fighting to aid others (such as the Lion that gives him his nickname), rather than to gain glory for himself. Eventually he proves himself to his wife, and she accepts her husband back into her castle.