Sir Gruffydd Llywd, or Gruffydd ap Rhyd ap Gruffydd ap Ednyfed (died 1335)[1] was a Welsh nobleman notable for his involvement in quashing Roger Mortimer’s 1322 revolt against King Edward II.[2] Throughout his life until his death in 1335, Llwyd held high-ranking positions in Welsh society, with Lordships in Tregarnedd and Dinorwig and serving as Sheriff of Caernarfonshire, Anglesey and Merionethshire.[3][4] Son of loyalist Rhys ap Gruffyd (died 1284), Gruffyd Llwyd was a supporter of King Edward I and King Edward II, helping to enforce conformity to English rule along the Welsh Marches.[3] Historical folklore has often mistakenly portrayed Llwyd as a ‘Welsh Rebel’ who challenged King Edward II, though this has been strongly disputed by historians.[2]