The Quarrel of Rhun and Elidir Mwynfawr
Elidir Mwynfawr, a man of the North, was slain here (i.e. in Gwynedd), and after his death the Men of the North came here to avenge him. The men who came as their leaders were Clydno Eiddyn and Nudd Hael son of Senyllt, and Mordaf Hael son of Serwa(n), and Rhydderch Hael son of Tudawal Tudglyd. And they came to Arfon, and because Elidir was slain at Aber Meuhedus in Arfon, they burned Arfon as a further revenge. And then Rhun son of Maelgwn and the men of Gwynedd with him, rose up in arms, and came to the bank of the Gwerydd in the North, and there they were long disputing who should take the lead through the river Gwerydd. And Rhun dispatched a messenger to Gwynedd to ascertain who were entitiled to lead. Some say that Maeldaf the Elder the lord of Penardd adjudged it to the men of Arfon: (I)owerth son of Madawg on the authority of the story affirms that it was Idno Hen to the men of the black-headed shafts. And thereupon the men of Arfon went in the van, and were good there. And Taliesin sang: "I heard the clash of their blades, With Rhun in the rush of armies, The men of Arfon of red spears".
NOTE
This is the same Rhun ap Maelgwn of Hanes Taliesin
SOURCE
The Chirk Codex (ca. 1200). trans. Rachel Bromwich. Trioedd Ynys Prydein. Cardiff: UWP, 1963. p.501-502.