were written between 211 and 222 under the Severan dynasty, with reference to his own day, and they were not entirely theoretical. Ulpian himself served as Praetorian Prefect and chief adviser to the Emperor Severus Alexander (r. 222–235), which cost him his life at the hands of the praetorian guard, whose privileges he had reduced.
Ulpian’s contemporary, Cassius Dio, (c. 155–c. 235), confirmed that the emperor was “absolved from the laws,” and that this position could be traced back to the earliest days of the Principate. (Dio 53.18.1.) The Lex de Imperio Vespasiani (law concerning the constitutional powers of Vespasian”), dating from the year 69, confers upon the emperor a rather less comprehensive exemption from the operation of the laws, limiting it to the laws from which Augustus, Tiberius and Claudius had been exempted. However, this important document, only about half of which has survived on a bronze plaque, also contains a clause (number VI) conferring on Vespasian (r. 69–79) the right and power to do and execute “…whatever he shall consider to be in accordance with the public interest and the dignity of divine and human, public and private interests,” just like Augustus, Tiberius, and Claudius. (CIL VI. 930 = ILS 244.) The less than pellucid language of this clause has aroused great controversy. What exactly is the scope of the power described here? Taken literally and in isolation, it would appear to confer on Vespasian an all-encompassing power. However, this is restricted by the clause about the emperor’s dispensation from the laws, which exempts him only from those laws from which Augustus, Tiberius, and Claudius had been exempted. And even Clause VI makes it clear that Vespasian is not being granted any more power than had already been possessed by Augustus, Tiberius, and Claudius. There is a negative subtext here, as only the “good” emperors are cited as precedents, while the names of Gaius Caligula, Nero, Galba, Otho, and Vitellius are all studiously omitted. So, Vespasian is possibly being warned here not to assume any powers that the “bad” emperors may have arrogated to themselves. On the other hand, the broad powers conferred by Clause VI are far more extensive than the constitutional position depicted in Augustus’s Res Gestae, discussed in Chapter 1. Although that document is a work of propaganda, the reason for the inclusion of Augustus’s name in the Lex de Imperio may also have an ulterior motive, possibly to attribute to the revered founder of the regime novel powers being conferred on Vespasian.
Whatever the precise constitutional position of the emperor may have been in the Principate, in practice, Diocletian’s position was not very different. What was of greater concern to him was to break the longstanding pattern of “absolutism tempered by assassination,” a description originally applied to Tsarist Russia but equally applicable to the Roman Empire in the third century before Diocletian’s accession.
The Tetrarchy
To solve this problem, Diocletian hit upon the novel expedient of the tetrarchy (not a term ever used by Diocletian), or four emperors sharing power, as illustrated in the famous more than life-size sculpture now in the Piazza San Marco in Venice, showing the four emperors in a group hug. The first step towards the tetrarchy was Diocletian’s appointment of his comrade in arms Maximian as his junior partner in 285, with Diocletian as “Augustus” and Maximian as “Caesar.” To cement the power relationship, Maximian added Diocletian’s family name, Valerius, to his own. The next step, in the following year, was to promote Maximian to share the title of Augustus with Diocletian, after which Diocletian took the name “Jovius” (associating him with the chief god, Jupiter) and Maximian became “Herculius,” linking him with the semi-divine mythical hero, Hercules. In 293, the foursome was completed with the appointment of Constantius and Galerius as Caesars. Though each of the four emperors had his own base of operations, which kept changing as the need arose, the empire was not divided but remained a unitary state. The tetrarchy worked as a temporary expedient in the face of several security threats, but it broke down after Diocletian’s abdication and peaceful retirement, itself a remarkable achievement, in 305.
Diocletian Chopped the Provinces into Pieces
Diocletian was also responsible for some major administrative reforms. Two are particularly noteworthy: rearranging the provinces and changing the provenance of office-holders. Besides his general hostility towards Diocletian for religious reasons, Lactantius (c. 250–c. 325) in his De Mortibus Persecutorum (Concerning the Deaths of the Persecutors) accused Diocletian of “chopping the provinces into pieces.” (Lactantius, de Mort. Pers. 7. 4–5.) The provinces were nearly doubled in number, and Diocletian separated civil from military responsibilities (a policy completed by Constantine), civil authority being vested in a governor with the title of praeses (plural: praesides), while the armed forces were under the command of a dux (plural: duces). The provinces were grouped into dioceses, of which there were twelve, under vicars (Latin: vicarius, plural vicarii) (deputies or lieutenants) because they were deputies to the praetorian prefects, their official title being vices agens praefecti paetorio (deputy to the praetorian prefect). Under Diocletian vicars and praetorian prefects combined civil and military authority, though this would change under Constantine. The praetorian prefects were essentially like chief ministers, or viziers, to the emperor. Initially, under Diocletian, there were two praetorian prefects, one attached to each Augustus. Under Constantine and his successors, there were always at least three, and more often four, praetorian prefects in office at the same time. After 312 the praetorian prefects’ military authority was transferred to a new purely military official called magister militum (master of the soldiers) or, more specifically, magister peditum (master of the infantry) and magister equitum (master of the horse). The power of the praetorian prefects was reduced still further by the creation by Constantine of the post of magister officiorum (Master of the Offices), as Grand Chamberlain or head of the imperial civil service.
The provinces which suffered the greatest reductions were, predictably enough, the old proconsular provinces of Africa and Asia. The former was divided into three provinces: Africa, Byzacena, and Tripolitana; the latter was even more finely fragmented, into six provinces: Asia, Helespontus, Lydia, Caria, Phrygia I and Phrygia II. (Verona Codex). The truncated provinces of Africa and Asia were the only proconsular provinces under the tetrarchy and, as such, exempt from the authority of praetorian prefects and vicars. All the new African and Asian provinces, like all the other provinces everywhere else except for those of Italy and Achaea, were praesidial.
Titles of Honor
In this study, the terms “noble,” “aristocrat,” and “member of the (senatorial) aristocracy” are used interchangeably to refer to someone of senatorial birth or senatorial origin, by which is meant someone whose father at least was a clarissimus (literally highly distinguished). While this usage of the term “noble” is a departure from the strict Republican use of nobilis to refer to the holder of a consulate or one of his descendants, it accords with the meaning of the word as used in the fourth century by writers such as Symmachus (c. 345–402) and the historian Ammianus Marcellinus (c. 330–c. 400). (Symm. Rel. III.7; Amm. XVI.10.13.)
While all nobles were clarissimi, not all clarissimi were nobles. By the time of Diocletian, the title vir clarissimus had been in common use for well over a century to refer to a senator or a man of senatorial rank. The title was hereditary as we know from the examples that we have of the title clarissimus puer (highly distinguished boy), dating back at least to 197 (ILS 1143). The clarissimate was not confined to men and boys, for we also find the titles clarissima puella (highly distinguished girl) and clarissima femina (highly distinguished lady), the latter title coming to a woman from her father or her husband.
The clarissimate was the late Empire’s equivalent to the laticlavium of the Principate, referring to the broad purple stripe on the tunic worn by senators. Just as, in that period, a novus homo (new man) could be awarded this honor by the emperor or be “adlected” (added), by the emperor to
