St. Eustace was a nobleman who suffered martyrdom at Rome, together with his wife Theopista, and two sons Agapius and Theopistus, about the reign of Adrian. The ancient sacramentaries mention his profuse charity to the poor on whom he bestowed all his large possessions some time before he laid down his life for his faith. An ancient church in Rome was built in his honor, with the title of Diacony. His body lay deposited in this church until the twelfth century when it was translated to that of St. Denis near Paris.