218-222 A. D.* Thereupon Elagabalus was universally
recognized as princeps and entered Rome in the following year. There he
introduced the worship of the sun as the supreme deity of the Roman world,
and added to the imperial title that of "most exalted priest of the
Unconquered Sun God Elagabalus." His rule was a riot of debauch, in which
his associates were worthless favorites, whom he appointed to the highest
offices. His grandmother, Julia Maesa, really conducted the government
and, realizing his unfitness to rule, forced him to adopt his cousin
Severus Alexander with the title of Caesar in 221 A. D. When Elagabalus
sought to rid himself of his relative the praetorians forced him to make
Alexander his colleague, and finally murdered him (March, 222 A. D.).

*Severus Alexander, 222-235 A. D.* Marcus Aurelius Severus Alexander was
now sole ruler. However, since he was a mere youth, his mother, Julia
Mamaea, daughter of Julia Maesa, exercised the powers of a regent. As he
grew up Alexander showed himself well-meaning and conscientious, but
lacking in self-reliance, and he never emancipated himself from his
mother's tutelage. During his rule the Senate enjoyed a temporary revival
of influence. Two councils of senators, one of sixteen and one of seventy
members, acted as an imperial cabinet and an advisory legislative council,
respectively. At this time, too, the praetorian prefecture became a
senatorial office in that it conferred senatorial rank upon its holder. An
attempt was made to remedy public abuses, in particular to restore
discipline among the troops, and to reduce the military expenditure. But
the army had gotten out of hand, especially the praetorians, from whose
anger Alexander was unable to protect the noted jurist Paul, who held the
praetorian prefecture.

*The new Persian empire.* The widespread military insubordination was all
the more dangerous since new and more aggressive foes began to threaten
the integrity of the empire. In 227 A. D. the Parthian dynasty of the
Arsacids was overthrown by the Persian Ardaschir (Artaxerxes) who founded
the dynasty of the Sassanids. The establishment of this new Persian
kingdom was accompanied by a revival of the national Persian religion,
Zoroastrianism, and of the Persian claims to the eastern Roman provinces.
In 231 the Persians drove the Roman troops out of Mesopotamia and
penetrated Cappadocia and Syria. Alexander himself then went to the East,
where he took the o