Ginsburg surmises that Paetus achieved the consulship through the influence of a group of senators that included the families of the Vitellii and Flavii.
In successive campaigns, Corbulo had established Roman rule over the country, and Paetus was placed in charge of defending it from Parthian counterstrokes.
In 62 however, Paetus, at the head of an army that included the legions XII Fulminata and IV Scythica, suffered a catastrophic defeat at the Battle of Rhandeia against the Parthian and Armenian forces of King Tiridates I of Armenia.
Charged with both incompetence and cowardice, Paetus was quickly pardoned by Nero, who dismissively commented that suspense would be harmful to someone of such timidity.
After reading the letters, Vespasian felt that he could no longer trust the family of Antiochus IV with the protection of the strategic crossings of the Euphrates River at Samosata, and thus resolved to directly annex Commagene.
Paetus married Flavia Sabina, born c. 30, the daughter of Titus Flavius Sabinus and Arrecina Clementina and paternal niece of Vespasian.