The two highest mountains in the range are named Carnedd Llewellyn and Carnedd Dafydd after the thirteenth-century Prince of Wales, Llywelyn ap Iorwerth or Llywelyn the Great (1172-1240), and his grandson Prince Dafydd ap Gruffudd (1238-1283). It was in a bog in the northern foothills of Bera Mawr, at a place called Nanhysglain, that Prince Dafydd ap Gruffudd and his family were captured in June 1283. In October, Dafydd was executed at Shrewsbury by Edward I and this ended the seven-hundred-year rule of Gwynedd by the family descended from Cunedda Wledig and the end of independence for Wales.