Meirchion

Meirchion was the father of King Mark of Cornwall, famous for his role in the story of Tristan and Iseult. He is thus assumed to have been an ancient king of Cornwall who reigned in the late 5th century, however the name of Mark's father derives from Old Welsh sources in which Mark is associated with Wales rather than the West Country.

He was the second son of Constantine Gorneu King of Dumnonia, brother of Erbin King of Dumnonia and Uthyr Benndreic, uncle of Arthur and Geraint. His son was Cunomor later known as Mark of Cornwall and his grandson was Drustan or Tristan of Arthurian myth.