Septimius Geta never held public office, but two cousins, P. Septimius Aper and C. Septimius Severus were members of the senate. Little is known of P. Septimius Aper save that he was a consul in 153. C. Septimius Severus was consul in 160 and governor of Numidia in 173-4, and, in 177, a member of the consilium of Marcus Aurelius. He secured the future emperor's admission to the senate in 169 and had him on his staff in 174. On his mother's side, the future emperor was related to Fulvius Plautianus, later his praetorian prefect.
Septimius himself was quaetor in 169. He was quaestor a second time in 170 or 171 and sent to Baetica in Spain. In 173-4 he was legate of his uncle in Numidia. He may then have been tribune of the plebs in 175 and praetor in 177, and served again in Spain in 178. In 182, he was legate of the future emperor, Pertinax, in Syria (and was dismissed with Pertinax before the year was over). While in Syria, however, he may have met Julia Domna, a member of the leading family of Emesa. In 185, Severus was sent to Gaul as governor of Gallia Lugdenensis, and in 187 he married Julia Domna. In 188 his first son, was born on April 4. In 189 he was governor of Sicily. His second son was born in March 189. He was consul in 190, and became governor of Pannonia Superior in 191. In 193, after the assasination of Pertinax, he siezed the throne from Didius Julianus.
contemporary historian Cassius Dio gives the impression that he was
deeply feared and respected by members of the senate, and, initially
at least, disliked by the urban plebs. Dio criticized the annexation
of Northern Mesopotamia for being too expensive, and provoking trouble
with Parthia. this may be an unfair judgement, as possesion of this
region became a crucial feature of Rome's defense in the third and
fourth centuries. At his death, he is said to have advised his sons
to pay attention to the soldiers and not to care much about the rest.
This may be a fair summary of his policies, which saw two major
changes in soldiers' lives: they were given the right to marry while
in service and received a massive increase in pay. This may have had
very serious consequences for state finances, but it did no more than
reflect the fact that their wages had not kept pace with inflation in
the previous century. The most serious criticisam of his domestic
administrative style may be that he placed too much power in the hands
of Plautianus, who appears to have abused his position, and that his
sons, clearly marked for succession well before his death, both appear
to have been unfit to administer the empire (and they hated each
other). On the other hand, his reign is notable for the rise in
influence of prominent jurists whose work provides the foundation for
later traditions of Roman law. The fact that he adopted his family
into that of Marcus Aurelius, and consistently had himself represented
in the style of Marcus reflects his concern for the legitimacy of his
claim to the throne.