Laelianus'
cursus honorum can be reconstructed from a pair of inscriptions recorded in Rome. His public career began with the
quatraviri viarum curandorum, one of the four boards that comprise the
vigintiviri; this board of four men was tasked with maintaining the city roads of Rome. This was followed by his commission in
Legio VI Victrix as a
military tribune. The record of his time with VI Victrix includes the note "
cum qua ex Germ. in Brittan. transiit": Laelianus was with the legion when it was redeployed from the Rhine frontier to its new base in
Roman Britain. Birley believes the governor at the time of this redeployment (AD 122) was
Aulus Platorius Nepos. Once he completed his service with this unit, he served as
quaestor for Gallia Narbonensis; he was the emperor's candidate for
plebeian tribune, and held the third and last of the Republican magistracies,
praetor. Once he completed his tenure in that office, Laelianus was appointed
curator of
Arausio. After this, he received a second commission as
legatus legionis or commander of
Legio I Minervia;
Géza Alföldy dates his command from around 138 to the year 141. After leaving his command, Laelianus was appointed governor of the imperial province of
Pannonia Inferior; Alföldy dates his tenure from around 141 to 144; this is confirmed by a
military diploma that mentions him as governor dated 7 August 143. His consulate followed. As an ex-consul, Laelianus held two more offices in the emperor's service. The first was as governor of
Pannonia Superior, and Alföldy dates his tenure in that province from 145 to around 150. The next office followed soon afterwards, as governor of the important province of
Syria from around 150 to some time after 153. Simultaneously with these offices, Laelianus advanced through the ranks of the ancient Roman priesthood. The first known
collegium he was a member of was the
fetiales, the priesthood known best for acting as heralds or ambassadors. He also was admitted to the
College of Pontiffs and became a member of the
sodales Antoniniani, the priests in charge of the cult of
Antoninus Pius. == The Parthian War ==