A poem by Cynddelw Brydydd Mawr notes a victory for Llywelyn ab Iorwerth (d.1240) in his struggle with his uncle, Dafydd ab Owain Gwynedd, in 1194 (Insley):

Ni bu lledrad cad cadr aber---Conwy,
Cynnechreu fy udd ner;
Cynnygn fy llyw oedd llawer,
Cwyddynt yn gnif seithrif ser (Jones and Owen, 241, line 9).

Translation:
The glorious one of Aberconwy's army was not a stealthy one
[At] the beginning of my lord-master's [career];
My leader's enemies were numerous
[But] the number of stars in the sky seven-fold fell in [the] battle. (Jones and Owen, 244, line 9).

The battle is also referred to by the poet Prydydd y Moch (Jones, 52, line 23 and 213, line 19), but is not mentioned in any of the chronicles.

RCAHMW (Battlefields Inventory), Feb 2017

Bibliography
Jones, Nerys Ann and Owen, Ann Parry (gol), Gwaith Cynddelw Mawr II (Caerdydd, Gwasg Prifysgol Cymru, 1995).
Charles Insley, `The Wilderness Years of Llywelyn the Great?, Thirteenth Century England IX (2001), 163-73.
Jones, Elin M. (gol.) Gwaith Llywarch ap Llewelyn `Prydyddy Moch? (Caedydd, Gwasg Prifysgol Cymru, 1991)