In Sep 1136 or Oct 1136 the Battle of Crug Mawr aka Cardigan was fought at Crug Mawr [Map] between Welsh and Normans for control of Ceredigion, West Wales.

The Itinerary of Archbishop Baldwin through Wales: Book 2 Chapter 3. We proceeded on our journey from Cilgerran towards Pont-Stephen [Map],¹²⁷ leaving Cruc Mawr [Map], i.e. the great hill, near Aberteivi, on our left hand. On this spot Gruffydd, son of Rhys ap Tewdwr, soon after the death of king Henry I., by a furious onset gained a signal victory [1136 Battle of Crug Mawr aka Cardigan] against the English army, which, by the murder of the illustrious Richard de Clare, near Abergevenny (before related), had lost its leader and chief.¹²⁸ A tumulus is to be seen on the summit of the aforesaid hill, and the inhabitants affirm that it will adapt itself to persons of all stature and that if any armour is left there entire in the evening, it will be found, according to vulgar tradition, broken to pieces in the morning.

Note 127. Our author having made a long digression, in order to introduce the history of the beaver, now continues his Itinerary. From Cardigan, the archbishop proceeded towards Pont-Stephen [Map], leaving a hill, called Cruc Mawr, on the left hand, which still retains its ancient name, and agrees exactly with the position given to it by Giraldus. On its summit is a tumulus, and some appearance of an intrenchment.

Note 128. In 1135.