ILLUSTRIS, was heretofore, in the Roman empire, a title of honour peculiar to people of a certain rank. It was first given to the most distinguished among the knights, who had a right to bear the latus clavus: afterwards, those were intitled illustrious who held the first rank among those called honorati; that is, the praefecti praetorii, praefecti urbis, treasurers, comites, &c.

There were, however, different degrees among the illustrious; as in Spain they have grandees of the first and second class, so in Rome they had their illustres, whom they called great, majores; and others less, called illustres minores.—For instance; the praefecti praetorii was a degree below the master of the offices, though they were both illustres.

The Novels of Valentinian distinguish as far as five kinds of illustres; among whom, the illustres administratores bear the first rank.