Background
He was the eldest son and heir of Hugh Bigod, 3rd Earl of Norfolk (1182-1225) by his wife Matilda, a daughter of William Marshal, 1st Earl of Pembroke (1147-1219), Marshal of England. His younger brother was Hugh Bigod (1211-1266), Justiciar. After the death of his father in 1225, the young Roger became the ward of William Longespée, 3rd Earl of Salisbury.