One fairly well-known example is that of King Mark of Cornwall. He appears prominently in the Arthurian legends about Tristan and Isolde. He is described as Tristan’s uncle by marriage.

Tristan and Isolde is a serviceable attempt at a medieval romance wrapped up in Arthurian legend, although the Scott ...

Two tales in the collection, The Dream of Rhonabwy and Culhwch and Olwen, are notable for featuring Arthurian legends. Of these, the story of Culhwch and Olwen is of particular interest ...