It is a story of knight-errantry, in which the protagonist Yvain is first rejected by his lady for breaking a very important promise, and subsequently performs a number of heroic deeds in order to regain her favour.

In the narrative, Yvain seeks to avenge his cousin, Calogrenant, who had been defeated by an otherworldly knight Esclados beside a magical storm-making stone in the forest of Brocéliande.

Yvain goes mad with grief, is cured by a noblewoman, and decides to rediscover himself and find a way to win back Laudine.

Jocelyn states that he rewrote the 'life' from an earlier Glasgow legend and an old Gaelic document, so that some elements of the story may originate in a British tradition.

The poem was translated into a number of languages, including the Middle English Ywain and Gawain; the Old Norwegian Chivaldric Ívens saga, and the Old Swedish Herr Ivan.