Dialgarreg (The Revenge Stone)

GEOGRAPHY CORRECTION - originally flagged as a Herefordshire/English-border lead ('the Hatterall Ridge Stone'), but the stone itself, and the killing it marks, are on the Welsh side, in Powys near Patrishow, in the Black Mountains. If it also has an English-side association via Hatterall Ridge (which does straddle the border), that wasn't confirmed independently here. One of the oldest and best-documented entries in this archive: it marks the ambush and killing of Richard fitz Gilbert de Clare, 3rd feudal baron of Clare, a major Anglo-Norman marcher lord, on 15 April 1136. Per Wikipedia (citing standard medieval-history references), Richard had returned to the Welsh border via Hereford and, ignoring warnings of danger, pressed on toward Ceredigion with only a small escort; he was ambushed and killed by the men of Gwent under Iorwerth ab Owain and his brother Morgan, grandsons of Caradog ap Gruffydd, in a wooded tract then called 'the ill-way of Coed Grano', near Llanthony Abbey, north of Abergavenny - the spot is explicitly identified by Wikipedia as being marked today by 'the garreg dial' (the stone of revenge). Richard's death triggered a major Welsh uprising: Owain Gwynedd and Gruffudd ap Rhys invaded his lordship and won a crushing victory over the Normans at the Battle of Crug Mawr near Cardigan; Richard's widow Alice had to be rescued from Cardigan Castle by Miles of Gloucester. Richard himself was buried far away, at Tonbridge Priory in Kent, which he had founded, so this stone is a pure site-marker rather than a grave. A 2021 Wales Online feature on the stone corroborates the story for a general audience; the site is also a listed waypoint on several published walking routes across the Black Mountains (Cwmyoy, Llanthony, Hatterall Ridge).