King Nudd succeeded his father, Senyllt, to the lowland border kingdom of unknown name centred around Selkirkshire in the mid-6th century. He was called 'Hael' - the Generous - and was celebrated in Welsh poetry, along with his cousins, Riderch and Morfael, as one of the 'Three Generous Men of Britain'.
These three, with Clydno Eityn of Din-Eityn (Edinburgh), were firm allies and, during the AD 560s, they took their mighty armies south and invaded Gwynedd in revenge for the killing of their cousin, Elidyr Mwynfawr. They devastated the country around Caer-yn-Arfon (Caernarfon) but were eventually driven out by King Rhun Hir.
An early 6th century monument discovered in Yarrow in Selkirkshire may refer to this character and his two sons, though the date is not quite right and they may be otherwise unknown relations. It is inscribed:
"This is the everlasting memorial: In this place lie the most famous princes, Nudus and Domnogenus; in this tomb lie the two sons Liberalis [the Generous One]."
He was also father of SS. Dingat and Llidnerth, and the lovely Teagu Eurfron, and was succeeded in his kingdom by the former.