Discusses the sexual relationship between Tristan and the Irish Iseut and the kinship bond between Mark and Tristan, and the political and economic structures of Celtdom as they contrast with Germanic feudal ones. In the text we see the collision of two quite distinct conceptions of sovereignty., which presents us with a double perspective whereby the lovers' behaviour has a possible legality in one of these perspectives, but is illegal when seen through the otherDans IMB 30/1, janvier-juin 1996, n° 3150