Tri Thlws ar Ddeg Ynys Prydain
The Names of the Thirteen Treasures of the Island of Britain, which were in the North:

Dyrnwyn, gleddyf Rhydderch Hael: White-Hilt, the Sword of Rhydderch the Generous: if a well-born man drew it himself, it burst into flame from its hilt to its tip. And everyone who used to ask for it would receive; but because of this peculiarity everyone used to reject it. And therefore he was called Rhydderch the Generous.

Mwys Gwyddno Garanir: The Hamper of Gwyddno Long-Shank: food for one man would be put in it, and when it was opened, food for a hundred men would be found in it.

Korn Bran Galed o'r Gogledd : The Horn of Bran the Niggard from the North: whatever drink might be wished for was found in it. <marginalia: The Horn of Bran the Niggard was one of the Thirteen Royal Treasures of the Island of Britain. And Myrddin came there to ask for those treasures of everyone who had them; and everyone agreed that if he should obtain the Horn of Bran the Niggard he should obtain theirs from them, supposing that he would never get the Horn. And nevertheless Myrddin obtained the Horn, and after that he obtained them all, and went with them to the Glass House, and they (i.e. the Treasures) remain there for ever. Hercules obtained the Horn of Bran the Niggard from the head of the centaur after he was 'slain. And then the wife of the Centaur wetted Hercules' shirt in the blood of the centaur, and when Hercules had put on the shirt it was not possible ever to take it from off him until the shirt had eaten his flesh and skin to the bone, and Hercules was slain.'>

Kar Morgan Mwynfawr: The Chariot of Morgan the Wealthy: if a man went in it, he might wish to be wherever he would, and he would be there quickly.

Kebystr Klydno Eiddin: The Halter of Clydno Eiddyn, which was fixed to a staple at the foot of his bed: whatever horse he might wish for, he would find in the halter.

Kyllell Llawfrodedd Farchog: The Knife of Llawfrodedd the Horseman, which would serve for twenty-four men to eat at table.

Pair Dyrnwch Gawr: The Cauldron of Dyrnwch the Giant: if meat for a coward were put in it to boil, it would never boil; but if meat for a brave man were put in it, it would boil quickly (and thus the brave could be distinguished from the cowardly).

Hogalen Tudwal Tutklyd: The Whetstone of Tudwal Tudglyd: if a brave man sharpened his sword on it, if it (then) drew blood from a man he would die. If a cowardly man (sharpened his sword on it), he (his opponent) would be no worse.

Pais Badarn Beisrydd: The Coat of Padarn Red-Coat: if a well-born man put it on, it would be the right size for him; if a churl, it would not go upon him.

Gren a desgyl Rhygenydd Ysgolhaig: The Crock and the Dish of Rhygenydd the Cleric: whatever food might be wished for in them, it would be found.

Gwyddbwyll Gwenddoleu ap Ceidio: The Chessboard of Gwenddolau son of Ceidio: if the pieces were set, they would play by themselves. The board was of gold , and the men of silver.

Llen Arthyr yng Nghernyw: The Mantle of Arthur in Cornwall: whoever was under it could not be seen, and he could see everyone.

These belong to the fifteenth and sixteenth centuries; the earliest manuscript contains only the names of the Treasures without the explanatory comments. The earliest versions refer to the Treasures "that were in the North" and the majority of names are from Y Cogledd. In a few of the later versions two other Treasures are added (the Mantle of Tegau Eurfon and Eluned's Stone and Ring), dropping one item and counting "the Crock and the Dish" as one item instead of two.

SOURCE:
Trioedd Ynys Prydein. trans. and ed. by Rachel Bromwich. Cardiff: UWP, 1961.