One of the earliest direct reference to Mabon can be found in the tenth century poem "Pa Gur", in which Arthur recounts the feats and achievements of his knights so as to gain entrance to a fortress guarded by Glewlwyd Gafaelfawr, the eponymous porter. The poem relates that Mabon fab Mydron (a misspelling of Modron) is one of Arthur's followers, and is described as a "servant to Uther Pendragon". A second figure, Mabon fab Mellt, is described as having "stained the grass with blood". He further appears in the medieval tale "The Dream of Rhonabwy", in which he fights alongside Arthur at the Battle of Badon and is described as one of the king's chief advisors.