The earliest known office Nigrinus held was as
plebeian tribune in 105;
Ronald Syme raises the possibility that he is the Nigrinus
Pliny the Younger praises for his speech indicting
Varenus Rufus for corruption during his administration of
Bithynia and Pontus. Nigrinus later became
proconsular governor of
Achaea, although it is unclear during what years this was; this was probably part of
Trajan’s attempt to recognize and stabilize the administration of the financially troubled province. Nigrinus was a trusted lieutenant of the Emperor Trajan. During the year of his consulship, Trajan sent Nigrinus to
Delphi, Greece as a member of an advisory council to assist the future historian
Arrian in settling boundary disputes. This event is recorded in Delphi, where there are honorific inscriptions dedicated to Nigrinus in Greek and Latin. Following his consulate, Nigrinus was appointed governor of
Dacia; he held this office from 113 until his death. In 117, Trajan died and he was succeeded by his paternal second cousin
Hadrian. In the summer of 118, Nigrinus was executed at Faventia on orders of the Senate. According to the
Historia Augusta Nigrinus was one of four senators who plotted to kill Hadrian while he was sacrificing, while adding that Hadrian had intended to make Nigrinus his heir apparent; the other three senators were
Aulus Cornelius Palma,
Lucius Publilius Celsus, and
Lusius Quietus. It is possible that Hadrian could have viewed Nigrinus as a potential threat, given his previous high standing and close relationship with Trajan.
Anthony Birley mentions the suggestion that Hadrian may have later felt remorse for this act, thus explaining why Hadrian adopted Nigrinus' son-in-law, Ceionius Commodus (who later, following his adoption of
Marcus Aurelius, took the name
Lucius Aelius). However, Birley also suggests Hadrian adopted Commodus out of "sheer perversity -- Hadrian's desire to infuriate other aspirants." == Family ==