"wearing the purple" may be a reference to martyrdom or a bishop's robe. In addition, in the later Roman Empire both Roman consuls and governors of consular rank also wore clothes with a purple fringe. The Notitia Dignitatum, a Roman catalogue of official posts, lists four or five provincial governors in Roman Britain and two of them were of consular rank. One was the governor of Maxima Caesariensis and the other that of Valentia. The parent who wore the purple may well have been one of these governors, whose names were not recorded. It has been suggested by historian Alex Woolf that Ambrosius may have been related to the 5th-century Romano-British usurpers Marcus or Gratian – Woolf expresses a preference based on nomenclature for Marcus. Frank D. Reno, an Arthurian scholar, has instead argued that the name "Aurelianus" indicates the descent of Ambrosius from the Illyrian Roman emperor Aurelian (reigned 270–275). Aurelian's military campaigns included the conquest of the Gallic Empire. N. J. Higham suggests that Ambrosius may have been distantly related to imperial families of the late Roman Empire, such as the Theodosian dynasty. Branches of this particular dynasty were known to be active in western Roman provinces like Hispania. Mike Ashley instead focuses on the name "Ambrosius" and its possible connection to Saint Ambrosius, a fourth-century Bishop of Milan, who also served as consular governor in areas of Roman Italy. The father of the Bishop is sometimes claimed to be a fourth century Praetorian prefect of Gaul named Aurelius Ambrosius, whose areas included Britain, though some modern scholars doubt that Saint Ambrosius was related to this man (instead identifying his father with an official named Uranius mentioned in an extract from the Theodosian Code). Ashley suggests that Ambrosius Aurelianus was related to the two Aurelii Ambrosii. Tim Venning points out that the name "Aurelianus" could be the result of a Roman adoption. When a boy was adopted into a new gens (clan), he received the family names of his new family but was often additionally called by a cognomen indicating his descent from his original family. The additional cognomen often had the form "-anus". When Gaius Octavius from gens Octavia was adopted by his uncle Gaius Julius Caesar, he was often distinguished from his adoptive father by the addition "Octavianus". In this case, Ambrosius may have been a member of gens Aurelia who was adopted by another gens/family.