IMPE´RIUM
IMPE´RIUM and IMPERA´TOR. Imperium is the
name of the power attaching to the higher magistrate of the Roman People, as
soon as he has been fully installed in office by the passing of a Lex
Curiata. It is qualified by the nature of the office to which it appertains
(Mommsen,
Staatsr. ii.3 p. 845): we have
a kingly imperium, a consular imperium, a praetorian imperium, and a
dictatorial imperium. In all cases it includes the capacity for both civil
and military command. The praetor, for instance, is equally qualified to
take command of an army and to administer justice between the citizens ; he
does both by virtue of the imperium of his office. The details of the manner
in which the imperium operates in the processes of Roman Law will be better
discussed under
JURISDICTIO
Here we have rather to consider the historical and constitutional aspects of
the question.
Imperium domi et militiae.--Instead of dividing
(as modern states commonly do) the functions of civil and military command,
the Romans merely distinguished locally two spheres of
[p. 1.996]administration. Outside the walls (
militiae,
“on service” ) the imperium exists in all its fulness. Its
civil and military powers are exercised at pleasure by every provincial
governor. Inside the walls (
domi) the imperium
is, under the Republic, limited by various restrictions; it is subject to
the
intercessio of a colleague, to
provocatio ad populum, and to extinction by the
lapse of the period of time assigned to the office. From the year 494 B.C.
the imperium at home is likewise crossed by the rival power of the
magistrates of the plebs. From all these restrictions the imperium abroad is
free. The difference between the two is not sufficient to make military rule
absolutely impossible in the city. On the occasion of a triumph the
magistrate (unless he be stopped by a tribune) rides with his army through
the street. When the city is actually attacked, it must of course be
defended by men enrolled under military discipline, and to the magistrate
with imperium the command of these men would necessarily belong; unless,
however, he got rid of
intercessio and
provocatio by being nominated dictator, he would be
somewhat hampered in the exercise of that command. But under ordinary
circumstances the distinction between the two localities was enough
practically to exclude military government from the space within the walls,
to confine the magistrate “at home” to the civil functions of
his imperium, and so to justify the verbal opposition of
domi and
militiae.
The magistrate legally qualified to act both
domi and
militiae was further bound
by constitutional custom not to confuse the two spheres, but to mark his
entry on the freer field of authority by a solemn exit under special
auspices, by the change of dress in which he laid aside the gown of peace
for the crimson mantle (
paludamentum), and by
the assumption of the axes which symbolised his enlarged powers. Under the
regulations of the later Republic, the occasions on which he was to transfer
himself from the one field of government to the other were not left to the
discretion of the magistrate, but were marked out for him by the law. The
praetor, for instance, who has the
urbana
provincia assigned to him, must remain at home administering
justice. Under Sulla's regulations the same appears to have been the case
with the consuls, unless the contrary was ordered by a senatusconsultum
“ut exeant paludati” (
Cic. Fam.
8.1. 0), which again could be frustrated by the veto of a
tribune. On the other hand, this march out must not be put off too long. If
the magistrate allows the last day of his year of office to pass while he is
still within the walls, his imperium will lapse along with his magistracy.
Probably Sulla's law prescribed a precise time in the December of each year
for the ceremony. These points are best illustrated by the situation
described in Cicero's speech
de Provinciis
Consularibus, ch. 15; and fully discussed in Mommsen's monograph
entitled
Rechtsfrage zwischen Caesar und den Senat.
Acquisition of the Imperium.--It would perhaps be going too
far to say that the imperium was conferred by a Lex Curiata. We find consuls
who have failed to obtain this nevertheless holding the senate and
conducting the general business of chief magistrate at Rome. It seems to
follow that by virtue of their election they can exercise much of the power
of their office, and it is that power which is called imperium. Nevertheless
it is clear that some of the main functions appertaining to the imperium
could not properly be performed unless the magistrate were empowered by a
Lex Curiata. Without this the praetor could not sit in judgment (
D. C. 39.19), the consul could not hold the
assembly for the election of his successors (
D. C.
41.43) nor triumph after a victory (
Cic. Att. 4.1. 6,
12). It even
seems that he could not without it properly take the command of an army at
all ( “consuli, si legem curiatam non habet, attingere rem militarem
non licet,”
Cic. de Leg. Agr. 2.1. 2,
30). Such rules might, however, be evaded. The Agrarian Law of Rullus (B.C.
63) provided indeed first that a Lex Curiata should be passed for the
commissioners, but ordained further that if it were not passed its effects
should nevertheless accrue to them. (Cic. ib. 11, 28, “quid postea si
ea lata non erit? . . . tum ii decemviri, inquit, eodem jure sint quo
qui optima lege.” ) This provision, though Cicero speaks of it as
monstrous, could be inserted in any law or plebiscitum creating an
extraordinary command. Even in the case of the consul, it was held that the
law of Sulla practically dispensed with the necessity for his getting a Lex
Curiata before he took command of his province and army. Appius Claudius,
consul in 54 B.C., who had been prevented by
tribunician intercessio from passing his Lex. Curiata, declared nevertheless
(
Cic. Fam. 1.9,
25), “se, quoniam ex S. C. provinciam haberet, lege
Cornelia imperium habiturum quoad urbem introisset.” The law of
Sulla manifestly only repeated the old doctrine [see
MAGISTRATUS] that the
magistrate
cum imperio, though he may be
prohibited from exercising his power except in his own provincia, does not
lose it (however long the lapse of time) till he comes again within the city
walls. But as the law says, “totidem litteris,” that he is to
be “cum imperio,” this is held by Appius to confer the imperium
by implication. Cicero, though he thinks that Lentulus may have a fighting
case if he wishes to dispute the claim of Appius to supersede him,
nevertheless is clearly of opinion that this claim is good in law (
“ne id quidem valde dubium est” ).
Collision of Imperium.--The rules as to the collision of
imperium, when two magistrates, inferior and superior, are acting in one
sphere, are the same as those for the collision of auspices [see
MAGISTRATUS]. When two
magistrates of equal power are acting together “at home,” their
relations are ruled by the principle of intercessio [see
MAGISTRATUS]. As the
imperium outside the walls is not subject to intercessio, a different
principle there obtains. Two equal magistrates must either agree between
themselves who is to command (
Liv. 22.30,
4), or must divide the army between them (ib. 27,
9), or must take command alternately (ib. 27, 6). In any case there is
always some one whom each soldier is bound to obey without question or
interference.
Transition to the Principate.--After the Second Punic War the
assignment of definite districts to each single magistrate becomes the rule,
and a double command is rare. Each
[p. 1.997]magistrate or
pro-magistrate
cum. imperio, having now his
locally defined province, is commonly bound not to interfere with his
colleagues by exercising any authority in their districts. Nevertheless we
have instances in which a coordinate or superior proconsular power is
committed to a person other than the proper governor of a province. This
infinitum imperium is ascribed by Cicero
(
in err. 2.3.8, and 3.91.213) to M. Antonius,
praetor of 74 B.C., who was commissioned against
the pirates. Pompey received it for the same purpose by the Gabinian Law
(B.C. 67). Pompey had an “aequum imperium cum proconsulibus”
(Vell. 2.31) on any ground within 50 miles of the sea. At a later period
(B.C. 57) the
imperium infinitum was again
granted to Pompey as curator of the corn supply of Rome, and it was even
proposed, though not carried, to give him a
majus
imperium over that of the ordinary governors (
Cic. Att. 4.1,
7). Such a superior command was actually voted to the proconsuls
Brutus and Cassius in the last days of the Republic. (See Mommsen,
Staatsr. ii.3 p. 655.)
The general rule, that the magistrate must govern his province personally,
was also broken through in favour of Pompey. From the year 55 B.C. till
Caesar's victory at Herda in 49 B.C. he was proconsul of Spain; yet he never
set foot in his province, but governed it through legati, while he remained
at Rome. In the year 52 he was both consul and pro-consul; for the remaining
years he was specially exempted from the rule that the imperium of the
promagistrate must lapse, as soon as its holder comes within the city walls.
Pompey set a yet more notable precedent for the system of the Principate,
when he lent to Caesar for service in Gaul a legion which had pronounced the
sacramentum in his name. The soldiers so
lent owed allegiance to Pompey even while serving in Caesar's army; and when
the senate required each of the two proconsuls to send a legion for service
against the Parthians, Pompey offered as his contribution that one which was
in Caesar's camp. Caesar at once acquiesced in the demand.
Proconsulare Imperium of the Principate.--In B.C. 27 the
senate assigned certain provinces to Augustus. He governed them, as Pompey
had done, by means of legati, who were invested with the subordinate
imperium
pro praetore. The Emperor remained in
the city without forfeiting his proconsular imperium, although it is not
clear whether the latter could be exercised over the city itself. Besides
his proconsular authority over his own provinces, Augustus had an
“infinitum imperium majus,” concurrently with his brother
proconsuls in the senatorial provinces (
D. C.
53.32,
5; cf. also the case of
Germanicus,
Tac. Ann. 2.43). The
infinitum imperium was especially convenient for the
command of the fleet which was concentrated in the hand of Augustus. Lastly,
every soldier in the empire had pronounced the sacramentum “in verba
Caesaris Augusti.” The precedent of Pompey's Gallic legion was
extended to the whole army: all were soldiers of the Emperor. He either
commanded them personally or by his legates, or else lent them to his
colleagues in the Proconsulare Imperium or to the proconsuls of the
senatorial provinces. Germanicus in Germany and Blaesus in Africa have each
an independent imperium, but have only borrowed troops. They may command
them in the field, but the Emperor retains the sole appointment of the
officers, the sole charge of the recruiting, and the sole right to discharge
men from the service. If these powers are ever exercised by another person,
it is only by delegation from the Emperor (Mommsen,
Staatsr.
ii.3 pp. 848-851).
The Emperor being regarded as continually a general at the head of his army,
not only keeps the insignia commonly associated with the name of Imperator,
the laurel wreath and laurelled fasces, but has various prerogatives which
may be deduced from those of the Republican general. The guard of honour
which escorted the commander in the field attends the Emperor at home, and
becomes the garrison of the town of Rome. [See
PRAETORIANI] The power of the general to settle his
invalided veterans on the lands he has conquered (as Scipio did at the
Spanish Italica: Appian,
App. Hisp. 38) is
interpreted as conferring on the Emperor the right to grant away the
ager publicus; and the power of rewarding
good service on the part of the auxiliary soldiers by the gift of
citizenship (Cic.
pro Balbo, 8, 19) develops
into the right to make Roman citizens at will.
It is noticeable that the
proconsulare imperium,
though it was in truth, as Mommsen says (
Staatsr. ii.3 p. 840), “the single definite qualification
absolutely necessary to the Princeps, and further sufficient by itself
alone to constitute the office,” is never mentioned by Augustus
himself in the account of his own offices and powers, which is preserved to
us in the Monumentum Ancyranum. The assignment of provinces was undoubtedly
within the competence of the senate, and it was now held (in extension of
the theory propounded by Ap. Claudius) that the senate might therewith
confer the power necessary for their government. The official silence gives
us to understand that it was a mere matter of administrative arrangement
that the charge of certain provinces and armies with the proconsular
imperium thereto appertaining was committed to Augustus. [
PRINCEPS]
Title of Imperator under the Republic.--Imperator means, of
course, “one possessed of the imperium.” Strictly speaking,
then, the title should be equally applicable “at home” and
“on service.” But from a very early period it was felt to
be “uncivil” in the magistrate to flaunt his authority in the
face of his fellow-citizens at home. The nickname of Imperiosus applied to a
Manlius who had unduly magnified his office (
Liv.
7.4,
3) shows the invidious associations of
the word. Hence the title of Imperator is never assumed by the magistrate
discharging civic functions, nor is the word ever used to describe him. In
the army, on the other hand, “Imperator” is the regular mode of
address of the soldier to the magistrate under whom he is serving. It is
quite clear from
Liv. 7.10,
10, and 7.16, 5, that this address was used from the first
moment that the general took the field, and not only after a victory. The
same may be gathered from Appian's story (
Bell. Civ. 4.40) of
a proscribed man, Rheginus (who had never, so far as we know, won a victory
or
[p. 1.998]enjoyed a triumph); one of his old soldiers is
described as recognising him with the words:
Ἄπιθι
χαίρων, αὐτοκράτορ :
τοῦτο γάρ μοι
προσήκει καὶ νῦν καλεῖν σε.
After a victory it was the custom for the troops to greet their commander
with a solemn acclamation. In so saluting they employed their every-day
title of address, and the cry “Imperator, Imperator,” sounded
from rank to rank. This ceremony relieved the general so honoured from the
obligation of veiling his imperium, and stamped upon him the appellation
thus publicly uttered. Henceforth he appends the word Imperator to his name,
and the title is used even by civilians who have occasion to address him. In
the later Republic the senate sometimes gives emphasis to the honourable
distinction by itself inviting or sanctioning the assumption of the title by
a victorious general. This assumption is commonly the first step towards
claiming a triumph. If it befall a man more than once in his life to achieve
successes in the field which thus authorise him to advertise his imperium to
the world, he sometimes indicates in adverbial phrase the repetition of his
honours, and signs himself “Imperator iterum” or
“Imperator ter.” Though not every possessor of the imperium
is justified in styling himself Imperator, the converse is strictly true; it
is impossible for any one to be called Imperator unless he is vested with
the imperium. No officer serving under the direct command of another without
independent auspices of his own may accept this address (it was refused to
the elder Drusus while still only a legate,
D. C.
54.33,
5), and no one who has the
title can retain it after he lays down his imperium. This occurs for the
proconsul the moment he comes within the city walls, unless his imperium be
extended for the day of triumph by decree of the people. [See
TRIUMPHUS] In this case the
title lapses with the imperium after that day.
Use of the title by Caesar.--The elder Caesar during the last
fourteen years of his life always styled himself Imperator. There is no
reason to suppose that in so doing he overstepped any legal restriction.
From the day of his victory over the Helvetii in B.C. 58 down to his death
he was continuously vested with the imperium, first as Proconsul, then as
Consul (B.C. 48), and then as Dictator. As the imperium never lapsed there
was no necessity to lay down the title, though his retention of it in the
city was “uncivil” doubtless, and arrogant. The title follows
Caesar's name in all official documents. [
PRINCEPS]
Praenomen Imperatoris.--With Octavian we come to
an entirely new use of the word. In the third year of the triumvirate (B.C.
40) he dropped his praenomen Caius and adopted instead the word Imperator as
a praenomen. Side by side with “Marcus Antonius Marci filius”
we now find “Imperator Caesar Divi filius.” Mommsen
(
Staatsr. ii.3 pp. 767-770) has
explained this strange transformation in a most ingenious conjecture. He
holds that Octavian chose to assume that the title Imperator had so
coalesced with the name of Caesar as to have become a sort of honorary
cognomen, like Magnus or Africanus. On this assumption he himself would have
a hereditary right to his adoptive father's appellation; and once granted
that Imperator was a part of the name, it might be transferred at will from
the place of cognomen to that of praenomen, just as Nero and Drusus were
used as praenomina by several members of the imperial family. Whether we
accept this explanation or not, there is no doubt of the fact that Augustus
employed the word Imperator as a proper name--
ὥσπερ
τι κύριον, as Dio Cassius (43.44) says of the emperors of his
own time. The next three principes did not adopt the
praenomen imperatoris, but retained each his own ordinary
praenomen of Tiberius or Caius. With Nero the practice of Augustus was
revived, and succeeding emperors likewise assumed this praenomen, some in
conjunction with, some in substitution for, the ordinary one.
Salutation Pro Imperio.--Though not every princeps assumed the
word Imperator as part of his name, yet every one of them possessed the
proconsulare imperium, and was therefore qualified to be addressed as
Imperator either by his troops or by the senate. It was the custom at the
beginning of each reign for the senate and soldiers to attest their
recognition of this qualification in a solemn greeting which exactly follows
the precedent of the greeting after a victory. The study of the imperial
coins has led the best authorities (see Mommsen,
Staatsr.
ii.3 p. 782) to the conclusion that, notwithstanding
the immense difference in the practical significance of the ceremony in the
two cases, the salutation
pro imperio and the
salutation after a victory are in law precisely the same thing, and that
they are counted as similar units by every emperor who signifies the number
of his acclamations among his list of honours. Thus, if we find Imp. IV.
attached to a name, we are to understand that the sum is made up by one
accession to the throne and three victories.
Whensoever the senate thus salutes a man as. Imperator, this is a solemn
proclamation that they have either conferred on him (as is their right) the
proconsulare imperium, or fully acknowledge him as already invested with it.
It is not unnatural that such a salutation by the senate should count as the
dies imperii, the day from which the
Emperor dates the commencement of his reign. In the register of the sacred
college of the Arval Brothers we find a feast “ob diem imperii
[Vitellii] . . . Germanici quod xiii. Kal. Mai. statutum est,”
and the date is found to synchronise with the day on which the senate heard
of the defeat and death of Otho and voted the customary decrees for his
successor (Henzen,
Acta Fratr. Arv. p. xciv.;
Tac. Hist. 2.55; Mommsen,
Staatsr. ii.3 p. 842). In the case of
Caligula the
dies imperii is still more clearly
defined. The 18th of March is honoured w<*> a festival,
“quod hoc die C. Caesar Augustus Germanicus a senatu Imperator
appellatus est” (Henzen, ib. p. xliii.).
The case is different when we find the soldiers giving this salutation to a
man who does not possess the imperium which is its legitimate foundation.
There are republican precedents to show that this need not in every case be
construed as an act of mutiny. In the 7th year of the Second Punic War,
after the defeat and, death of P. and Cn. Scipio in Spain, the remnant of
the Roman army placed at their head a knight
[p. 1.999]named
Marcius, who extricated them from their danger. When Marcius sent letters to
the senate announcing these events (
Liv. 26.2),
he signed himself
pro praetore, thus assuming
that he had
de facto acquired the imperium
necessary to justify his command of the troops. As he styled himself
pro praetore his soldiers would doubtless
address him as Imperator, indicating thereby their intention to treat him as
if he were their lawful commander. The same lesson may be gathered from the
story of the first meeting of Sulla and Pompey. Pompey had on his own
authority raised an army in Picenum, had baffled the superior forces opposed
to him, and effected a junction with Sulla. When the two met, Pompey of
course addressed the victorious proconsul as Imperator: Sulla made use of
the same title in reply, thus acknowledging Pompey, not as a mere officer of
his own, but as invested with an independent command. In both these cases
the
de facto imperium was presumed without any
intention of rebellion against legal authority, but in obedience to the
supposed necessities of the situation, and with the intention of having the
assumption afterwards properly ratified. In somewhat the same way under the
Principate, troops whose command was vacant by the death of him whose
soldiers they had been, might, irregularly but without any gross breach of
constitutional order, offer a provisional allegiance to a new commander.
This was done by the praetorians to Claudius after the assassination of
Caligula. In the present decay of its practical power no choice was left to
the senate but to confirm the initiative of the soldiers. This initiative is
all the more justified when the person chosen (as Nero, for instance)
already possesses the proconsular imperium as colleague of his predecessor.
In this case, as no new imperium begins, the event is not counted in the
list of acclamations (Mommsen,
Staatsr. ii.3 1155). More generally, however, the soldiers in giving this
salutation discard a prior allegiance. Here, too, we may find an early
parallel in the story told by Livy (
7.39), of a
military insurrection during the Samnite War. The mutineers seized on a
retired officer named Quinctius, and offered him the choice of death or
imperium et honorem. Forced to submit, he
was at once saluted “Imperator,” and carried to the camp. In
like manner when the army of Germany, for instance, greeted its legate
Vitellius as Imperator, this acclamation was an act of revolution and civil
war. It ascribed the
proconsulare imperium to
one who not only did not already possess it, but who could not possess it
without supplanting his legal commander. It further proclaimed the intention
of these soldiers to prove their assertion good at the point of the sword.
Vitellius, as we have already seen, dated his reign not from this first
salutation, but from the day when his authority was acknowledged by the
senate. It was no doubt the more correct and more modest proceeding that the
Emperor should thus ignore the irregular inception of his reign, and refer
his power to the moment when it was legitimately conferred. But we also find
another theory prevalent. From the moment when the pretender has accepted
from any voice the salutation of Imperator, he has claimed to be in
possession of the magisterial authority which serves as a basis for that
title. If these pretensions are afterwards made good, he may without any
great breach of propriety look upon them as having received a retrospective
sanction, and may refer back to the moment of claim as the moment of
acquisition. So we are told (Suet.
Vesp. 6) that Vespasian
kept as his
dies imperii the day (July 1st)
when he was first saluted Imperator by the legions of Egypt, though for
months later the senate and the city of Rome were under the control of his
rivals.
History of the Title under the Principate.--The supreme
importance of the proconsulare imperium and of the functions attached to it
added lustre to the derived name of Imperator. It might indeed attach to
other persons than the reigning princeps. The Emperor's colleagues might
accept the solemn salutation after a. victory and assume the title of
honour. Tacitus tells us (
Ann. 1.3) that Augustus
“privignos imperatoriis nominibus auxit,” and again (2.26)
of the younger Drusus, that he “nonnisi apud Germanos assequi nomen
imperatoris et deportare lauream posse.” The title is frequent on
their coins, and the word is sometimes used to describe them (
Tac. Ann. 2.17,
2;
3.12,
4). It is also clear that Imperator was the everyday mode of address
which the soldiers used towards them no less than towards the princeps.
Velleius tells (2.104) that when Tiberius was sent by Augustus to take
command of the army of Pannonia, his old soldiers crowded round him,
exclaiming, “Videmus te, Imperator, salvum recepimus . . . ego tecum,
Imperator, in Armenia,” &c. The same was probably the
case with the senatorial proconsuls of Africa. The soldiers would not have
been likely publicly to salute Blaesus Imperator, as they did after his
victory over Tacfarinas (
Tac. Ann. 3.74),
unless they had been used to call him by that name in private. On this
occasion Tiberius allowed to Blaesus the assumption of the title, but the
precedent was not afterwards followed. By the time of Domitian the word had
become so distinctive an emblem of the supreme power that an unfortunate
senator was put to death because by a slip of the tongue on the part of the
crier he had been proclaimed Imperator instead of Consul. Gradually the
proconsular and military associations connected with the words
“imperium” and “imperator” fall away. In the
jurists of the 2nd century “imperium” and “imperatoria
potestas” denote the whole of the powers conferred on the chief
of the state (Mommsen,
Staatsr. ii.3 p.
877, n. 1). “Imperator” becomes the title of the chief
magistracy, and to a great extent supplants that of “princeps”
by which Augustus had chosen to describe himself.
[
J.L.S.D]
