To inform the consideration of The inventory of Historic Battlefields in Wales, a phased programme of investigation was undertaken on the battle of Bryn Glas. Detailed reports of these investigations are available and comprise documentary and historical research (Border Archaeology, 2009), two phases of non-invasive and invasive fieldwork (Archaeology Wales, 2012 and 2014) and excavation (Archaeology Wales, 2013).

The battle is covered in several contemporary and near-contemporary English and Welsh chronicles (Border Archaeology, 2009). The most detailed account of the battle is the Historia Vitae et Regni Ricardi Secundi, written at the abbey of Evesham c.1413, which records on 22nd June 1402, Edmund Mortimer was captured when:

Owain Glyndwr had descended from the mountains of Wales with a few men, and he was on one of the mountains beside Pilleth? he fearlessly ascended the mountain. And so when the two forces came together with a great charge, the aforesaid Welshmen of Maelienydd? turned against their own lord? Edmund was captured publicly, and many others with him. .. around four hundred Englishmen were slain, among them were four knights, including the Lord Kynard de la Bere (Livingstone and Bollard, 78-9)

It is difficult, based on the available documentary and archaeological evidence, to determine exactly where the battle was fought. The Wigmore Chronicle names the battle site as `upon the hill called Bryn Glas in Maelienydd near Knighton?, which is identifiable with the hill immediately to the west of the parish church of St Mary (SO 254 682) but where non-invasive and invasive archaeological fieldwork has found no evidence (Archaeology Wales, 2012 and 21013). A note by Nicholas Bysshop written c.1432, places it `on a hill with a spring and on the right side of an adjacent hill? (Graig Hill, SO 253 689) (Griffiths, 116) and the Prose Brut locates it `on the Blacke Hyll? (SO 248 693) (Brie, 393). The most likely site is somewhere in the vicinity of these three hills.

RCAHMW (Battlefields Inventory), Jan 2017