These triads, which Iolo put forth as medieval works, present Hu as a culture hero of the ancient Britons who introduced ploughing.

Still, Iolo's version of Hu Gadarn was taken up in the 20th century by the poet Robert Graves, who associated him with other Celtic figures; since then he has been popular among neopagans.

[3] In this story, part of the literary cycle known as the Matter of France, Hu Gadarn (Hugo or Hugun le Fort in the French) is Emperor of Constantinople and an enemy of Siarlymaen (Charlemagne).

[2][4] Other early references to "Hu Gadarn" have been cited in poems by Rhys Brydydd and Llywelyn ab y Moel, both of whom associated him with semi-divine attributes during the 15th century.

[5] Here, Hu is presented as a culture hero who leads the ancient Britons to Britain from their previous home in Deffrobani, glossed as "Summerland", and said to be situated "where Constantinople is now" (though the name has also been identified as a Welsh form of Taprobana).