Peter of Montfort stoutly resisted a Welsh attack at Abergavenny, led by Gronw ab Ednyfed and the princes of south Wales, in late February 1263.
Source: J.E.Lloyd, A History of Wales, vol II, 1912, p.731.
Other sources, as yet unverified, suggest that Roger Mortimer and the Marchers counter-attacked and defeated the princes of Deheubarth at Abergavenny in March 1263.
Battlefields Trust records refer to a battle in 1263 on the "Blorenge Mountains" (nprn 404987), which are some 3km to the south west of Abergavenny; there may be a connection with the battle(s) mentioned above.
B.A.Malaws, RCAHMW, 09 October 2006.