The lid of this casket has heraldic devices which inform us about the personal history and the date of the casket. The arms at the front of the lid belong to Isabella, daughter of Philip IV, king of France from 1285 to 1314. Isabella was betrothed to the future King Edward II of England in 1303, and married in 1308. The casket is likely to date from these years. The arms on the other side of the casket relate to Margaret, the second wife of Edward I of England (reigned 1272-1307) and half-sister of Philip IV of France. The casket could have been an appropriate gift for her to make to Isabella on the occasion of either her betrothal or marriage to Prince Edward. Inside the casket there are traces of three compartments which may indicate that it was used originally as a chrismatory (container for holy oils). The sides of the casket are decorated with motifs drawn from medieval window tracery.