Revaluating one of Professor Nitze's earlier suggestions, I have tried to use the concept of sovereignty for the understanding of the composition of Chrétien's Erec. This controversial concept, a husband's patriarchal sovereignty in the atmosphere of Arthurian courtliness, will be shown in this paper to be a constituent factor in Yvain, the most mature of the romances completed by Chrétien himself. Hitherto not discussed in the impressive literature, this question, one of sens, cannot be developed without some discussion of the several widely divergent views on the matière and will seem less confusing, if we begin by studying the final phase (vss. 6527 ff.), and, then, work retrospectively toward the main plot and the beginning of the romance.