166. Datianus is mentioned in Gruter's Inscriptions as
having determined the limits between the territories of Pax
Julia and those of Ebora, both cities in the southern part
of Lusitania. If we recollect the neighbourhood of those
places to Cape St. Vincent, we may suspect that the
celebrated deacon and martyr of that name has been
inaccurately assigned by Prudentius, etc., to Saragossa or
Valentia. See the pompous history of his sufferings, in the
Memoires de Tillemont, tom. v. part ii. p. 58-85. Some
critics are of opinion that the department of Constantius,
as Caesar, did not include Spain, which still continued
under the immediate jurisdiction of Maximian.