The site is marked on early Ordnance Survey 6in and 25in maps as "Traed y Milwyr Supposed Site of Battle" and some 400m to the northeast is a ford on the river Rhymney annotated "Rhyd y Milwyr".
A large common called Mynydd y Gaer on the north side of Gelligaer parish is believed to be an ancient battle site.
Source: Archaeologia Cambrensis Supplement, 1911, part 3, p.14.
A battle between the Welsh and Anglo-Norman armies was fought at Gelligaer towards the end of the 11th century, resulting in a victory for the Welsh.
Samuel Lewis, A Topographical Dictionary of Wales, 1849.
Other sources, as yet unverified, suggest that the only authority for the battle (the "Gwentian Brut") has proved to be a forgery and hence the battle can be disregarded.
B.A.Malaws, RCAHMW, 01 September 2006.
