Welsh historian who served as President of the Royal Historical Society and Chairman of the Ancient Monuments Board. His historical publications include Wales: the Age Of Conquest and Lords and Lordship in the British Isles in the Late Middle Ages.
He studied at Merton College in Oxford before becoming Professor of History at the University College of Wales in 1975.
His 1987 book, Conquest, Coexistence and Change: Wales 1063-1415, won the Wolfson Literary Award for History.
He married Carys Lloyd Wynne in 1966. He and Wynne later became parents to a son and a daughter.
He and Daniel Pipes were both influential historians.