h was of such scope and duration that it made
him the commander-in-chief of the forces of the empire.

*The titles Augustus and Imperator.* On 16 January of the same year the
Senate conferred upon Octavian the title of Augustus (Greek, _Sebastos_)
by which he was henceforth regularly designated. It was a term which
implied no definite powers, but, being an epithet equally applicable to
gods or men, was well adapted to express the exalted position of its
bearer. A second title was that of Imperator. Following the republican
custom, this had been conferred upon Augustus by his army and the Senate
after his victory at Mutina in 43 B. C., and in imitation of Julius Caesar
he converted this temporary title of honor into a permanent one. Finally,
in 38 B. C., he placed it first among his personal names (as a
_praenomen_). After 27 B. C. Augustus made a two-fold use of the term; as
a permanent _praenomen_, and as a title of honor assumed upon the occasion
of victories won by his officers. From this time the _praenomen_ Imperator
was a prerogative of the Roman commander-in-chief. However, during his
principate Augustus did not stress its use, since he did not wish to
emphasize the military basis of his power. But in the Greek-speaking
provinces, where his power rested exclusively upon his military authority,
the title Imperator was seized upon as the expression of his unlimited
_imperium_ and was translated in that sense by _autocrator_. From the
_praenomen_ imperator is derived the term emperor, commonly used in modern
times to designate Augustus and his successors.

*The tribunicia potestas, 23 B. C.* From 27 to 23 B. C. the authority of
Augustus rested upon his annual tenure of the consulship and his
provincial command. But in the summer of 23 B. C. he resigned the
consulship and received from the Senate and people the tribunician
authority (_tribunicia potestas_) for life. As early as 36 B. C. he had
been granted the personal inviolability of the tribunes, and in 30 B. C.
their right of giving aid (_auxilium_). To these privileges there must now
have been added the right of intercession and of summoning the _comitia_
(_jus agendi cum populo_).(15) In this way Augustus acquired a control
over comitial and senatorial legislation and openly assumed the position
of protector of the interests of the city plebs. He was moreover amply
compensated for the loss of civil power which his resignation of the
consulship involved, and at