Llewelyn ap Iorwerth, known as Prince Llewelyn the Great, granted the Abbott and monks the land in Rhos , as well as that in Aberconwy. The first charter was in 1186. Llywelyn’s chief counsellor Ednyfed Fychan, his seneschal, or chancellor, is traditionally said to have slain three chief captains of Ranulf, Earl of Chester in a battle in 1210 (which is said to be the origin of his coat of arms).
Ednyfed was one of Llewelyn’s bravest generals, and an ancestor of Henry VII and the house of Tudor. He had several manor houses in Denbighshire (as well as Caernarvonshire and Anglesey) but the chiefest of these was on Bryn Euryn. The first historical reference to ‘Ros Venych’ was in a charter of 1230 in which Llewelyn sanctions the purchase of the land by Ednyfyd. In those days the parish was known as Dinerth or Dinarth, the fort of the bear, and the name was changed to Llandrillo during the reign of Henry VIII.
The charter is addressed to ‘all sons of holy Mother Church…
Let your brotherhood know that Idneved Vachan our Seneschal purchased without assent from the heirs of Dineyrth…the land of Ros Venych with all belongings and liberties in wood, in plain, in grazings, pastures, meadows, paths and waters, and in all easements on sea and on land…